(navigation image)
Home American Libraries | Canadian Libraries | Universal Library | Community Texts | Project Gutenberg | Children's Library | Biodiversity Heritage Library | Additional Collections
Search: Advanced Search
Anonymous User (login or join us)
Upload
See other formats

Full text of "A Textbook on anatomy, physiology, and hygiene for the use of schools and colleges"

Google 



This is a digital copy of a book that was preserved for generations on library shelves before it was carefully scanned by Google as part of a project 

to make the world's books discoverable online. 

It has survived long enough for the copyright to expire and the book to enter the public domain. A public domain book is one that was never subject 

to copyright or whose legal copyright term has expired. Whether a book is in the public domain may vary country to country. Public domain books 

are our gateways to the past, representing a wealth of history, culture and knowledge that's often difficult to discover. 

Marks, notations and other maiginalia present in the original volume will appear in this file - a reminder of this book's long journey from the 

publisher to a library and finally to you. 

Usage guidelines 

Google is proud to partner with libraries to digitize public domain materials and make them widely accessible. Public domain books belong to the 
public and we are merely their custodians. Nevertheless, this work is expensive, so in order to keep providing tliis resource, we liave taken steps to 
prevent abuse by commercial parties, including placing technical restrictions on automated querying. 
We also ask that you: 

+ Make non-commercial use of the files We designed Google Book Search for use by individuals, and we request that you use these files for 
personal, non-commercial purposes. 

+ Refrain fivm automated querying Do not send automated queries of any sort to Google's system: If you are conducting research on machine 
translation, optical character recognition or other areas where access to a large amount of text is helpful, please contact us. We encourage the 
use of public domain materials for these purposes and may be able to help. 

+ Maintain attributionTht GoogXt "watermark" you see on each file is essential for in forming people about this project and helping them find 
additional materials through Google Book Search. Please do not remove it. 

+ Keep it legal Whatever your use, remember that you are responsible for ensuring that what you are doing is legal. Do not assume that just 
because we believe a book is in the public domain for users in the United States, that the work is also in the public domain for users in other 
countries. Whether a book is still in copyright varies from country to country, and we can't offer guidance on whether any specific use of 
any specific book is allowed. Please do not assume that a book's appearance in Google Book Search means it can be used in any manner 
anywhere in the world. Copyright infringement liabili^ can be quite severe. 

About Google Book Search 

Google's mission is to organize the world's information and to make it universally accessible and useful. Google Book Search helps readers 
discover the world's books while helping authors and publishers reach new audiences. You can search through the full text of this book on the web 

at |http: //books .google .com/I 



A TEXT-BOOK 



■ .:!,% i'AxAlJ 

■ ■ .;; n;v£ 



ON 



ANATOMY, PHYSIOLOGY, and HYGIENE 



FOR THE USE OF 

SCHOOLS AND COLLEGES 



BY 

JOHN C. DRAPER, M.D., LL.D. 

PBOmSOB OF RATI7RAL HIBTOBT AKD PHT8I0L0OT 15 THK COLLSOK OF THS aTT OF VKW YORK 

ASD PB0FSB80R OF rHKMISTRY Ut THK MEDICAL DKPARTlfKKT OF THE 
UinTXBaiTT OF THB CITY OF KXW YORK 



WITH ONE HUNDRED AND SIXTY-FOUR ILLUSTRATIONS 



SIXTH EDITION, REVISED 



^- - ^ :. .... ':rD UNIVERSITY 



NEW YORK 
HARPER & BROTHERS, FRANKLIN SQUARE 

1891 



] 



Entered, according to Act of Ckingress, in the year one thousand eight hundred and 

sixty-six, by 

Harpir & Brothers, 

In the Clerk^s Office of the District Court of the Southern District of New York. 



Copyright, 1883, by Harper & Brothers. 



PREFACE. 



Having been engaged for many years in teaching the various 
-ranches of Natural History, and having experienced the diffi- 
"-lilty that exists in attempting to teach Anatomy and Physi- 
:>logy without a text-book adapted to the wants of collegiate 
classes, I have ventured to publish my course of lectures on 
these subjects in the form herein presented, that collegiate stu- 
dents may have every opportunity of perfecting themselves 
in these branches as thoroughly as the limited time devoted to 
them will permit. 

Anatomy and Physiology have been subjects of study for 
many centuries, and there is but little that an author can say 
regarding them that is novel or original. I therefore acknowl- 
edge my indebtedness to the works of Carpenter, Cruveilhiei*, 
Foster, Hermann, J. W. Draper, and many other men of science, 
whose labors and writings are quoted, and whose opinions have 
been adopted. 

Although the chief object has been to prepare a text-book 
for academic students, the work is also designed for the use of 
schools and families. The division of Hygiene will be found 
to present many facts of interest to the general reader. 



REVISED EDITION. 

It is now eighteen years since this woi'k was first presented 
to the public. During that time many changes have occurred 
in opinions regarding Anatomy, Physiology, and Hygiene. 
Advances in the construction of microscopes have inci'eased 



IV PEEFACE. 

our opportunities for the investigation of the minute anatomi- 
cal structure of the various tissues entering into the construc- 
tion of the body. Discoveries in Physics and Chemistry have 
modified and advanced our means for explaining the action of 
the various organs. Particularly is this to be seen in the case 
of the special senses. A more general investigation of matters 
connected with Hygiene has led in its turn to improvements in 
that department of science. 

These facts show the necessity for a thorough revision of the 
work, if it is intended to make it a fair presentation of the 
matters in question. It is with this object in view that this 
edition has been prepared. 

College of the Citt of New York, 1883. 



CONTENTS. 



LmC«t« IV* 

1. Introduction 1 

2. Cells 3 

8. Human Body 7 

4. TheSkeleton 15 

5. Extremities and Joints 21 

6. The Muscular Svstem 25 

7. Organs of Nutrition 34 

8. The Intestines 41 

9. Glands and Secretions 45 

10. Food 49 

11. Divisions of Food 51 

1 2. Digestion 56 

13. l^esidues. Capillarity, Osmosis C2 

14. Absorbtion 06 

16. Blood 70 

16. Thelleart 76 

17. Blood-vessels of Body 82 

18. *' of Extremities 89 

19. Circulation of the Blood 92 

30. Secretion and Excretion 99 

21 . Hespiratory Apparatus 104 

22. The Respiratory Process 107 

23. Respiration continued Ill 

24. Animal Heat 117 

25. The Urinary System 121 

26. Action of Kidney and Liver 124 



Lsriara 

27. The Nenrons System 127 

28. Action of Nervous System 136 

29. The Special Senses 140 

30. Taste and Smell 143 

31. Properties of Sound 146 

32. Anatomy of the Ear 150 

33. Hearing and Voice 154 

34. Nature and Properties of Light 159 

35. Spectrum and Lenses 164 

36. Anatomy of the Eye 168 

37. Action of the Eye 1 72 

38. The Course of Human Life 1 78 

39. Influence of External Agents on Man 183 

40. Hygiene of Food 187 

41. Animal Food 195 

42. Vegetable Food 202 

43. Fluids used as Drink 207 

44. Alcoholic Stimulants and Toluicco.. 212 

45. Hygiene of Respiratory System. ... 217 

46. Disinfectants and Malaria 222 

47. Hygiene of the Skin 227 

48. Bathing. 231 

49. Clothing 287 

50. Hygiene of Muscular, Osseous, and 

Ner\'ous Systems 242 

51. Prophylactics 246 



LIST OF ILLUSTRATIONS. 



Cells showing Nuclei 8 

4t »t it / O 

Reproduction of Cells by Section 4 

" Granulation 6 

Moral Tissue 5 

Varieties of Confen-a, showing the Shnpe 

of Cells and Nuclei 5 

Yellow Fibrous Tissue 6 

Section of Bone mngnified 50 Diamerere, 

showing Haversian Canals 1 1 

Section^ of Bone magnified 2aO Diame- 
ters, showing Lacuna: and Cannlicnli.. 11 
Cartilage ossifying, magnified 10 Diame- 
ters '. 12 

The Skeleton 13 

l3ase of the Skull, showing the Occipital 

Bone and Foramen Magnum 16 

The Sphenoid Bone 16 

The Ethmoid Bone 16 

Lateral View of Skull 16 

Temporiil Bone 16 

Parietal Bone, Inner Siirfnce 17 

Superior Maxillary, Outer and Inner Sur- 
face ", 17 

Inferior Maxillary 17 

The Nasal Bone^ 17 

The Palate Bones 18 

The Malar Bone 18 

The Vomer 18 

Cer\*ical, Lumbar, and Dorsal Vertebrie. . 18 

The Vertebral Column 19 

The Os Innominatum 20 

The Sacrum and Coccyx 20 

The Scapula '. 21 

The Clavicle 21 

The Humerus 21 

The Femur 22 

The Foot 23 

White Fibrous Tissue magnified 300 Di- 
ameters 24 

Lever of 1st Class 24 

*' 2d Class 24 

" 3d Class 24 

Blood-Tessels of Muscular Tissue 26 

Kectangular Cells of Voluntary Muscle. . 26 

Striped Muscular Fibre 26 

Involuntary Muscle Cells 26 

Unstriped Muscle 26 

The Muscular System 27 

" ** ** 31 

The Digestive Tract 34 

The Hydra 35 

Parts composing Teeth 36 



Incisor Teeth 37 

Canine Teeth 87 

Bicuspid and Molar Teeth 87 

Human Lower Jaw 88 

Jaw of Rat 88 

Section of Stomach 89 

Muscular Bands of Stomach 40 

Mucous Membrane of Stomach magnified 

70 Diameters .... 40 

Sections of Stomach Follicles magnified 

160 Diameters 41 

The Duodenum 43 

Section of Wall of Ileum magnifl^ 60 

Diameters 43 

Parotid Gland 45 

The Liver 47 

The Pancreas 48 

Brunner's Glands. . l^^ 49 

Follicles of Lieberkuhn 49 

Peyer's Plates 49 

Stomachs of Ruminant 60 

** Kangaroo 61 

Digestive Tract of Common Fou 1 62 

Elevation of a Wetting Liquid 64 

Depression of a Non-wetting Liquid . 64 

The Endosntometer 65 

Villus showing Termination of the Lac- 
teal Tube 68 

Villus showing Blood-vessels .^. .. 68 

** ** External Cylindroid Epi- 
thelium .' 69 

Thoracic Duct 69 

Chyle Corpuscles 70 

Human Blood Discs mngnified 500 Di- 
ameters 74 

The Heart 77 

Heart' of Dugong 78 

Right Side of Human Heart 79 

Left ** ** ** 80 

Valves of the Heart 81 

The Circulatory System 83 

Carotid Arteries. . .' 86 

Superior Mesenteric Artery 88 

Motion in a Capillary Tube 93 

Principle of Venturi 93 

Capillary Circulation in a Frog's Foot. . 94 

Section of Mammaiy Gland 1 00 

Colostrnl Corpuscles of Milk 100 

Transplantation of Tissues 101 

Skin of Palm mngnified 20 Diameters. . 102 

Section of Human Hair 102 

Section of Skin magnified 10 Diame- 
ters 103 



VIU 



LIST OF ILLUSTRATIONS. 



Sudoriimroas Gland magnified 20 Diam- 
eters 1 03 

Side View of Lurynx 104 

Hack View of Lannx 104 

Trachea, Bronchi, and Bronciiiai Tubes.. 105 
Capillarv Bronchi and Air-celU of n 

I>»hule lOo 

Capilhiry Blood-vessels of Air-cells IOC 

Helati%'e Position uf the Ueart and Lnngs 106 

Mechanism of Kespiratorj Apparatus. . . 1 08 

Simple Diffusion.... 108 

Diffusion uf Gases through Porous Bur- 
ners 1 01) 

Diffusion through Poreless Strnctures. . . 109 

** against Pressure 110 

The Respiratory Machine 112 

Air-sac of Fish 118 

Lung of Iteptile 118 

Lung of Fr(»g 119 

Section of Kidney 1 22 

Diagram of Convoluted Tube and Tuft. . 1 22 

Convoluted Tubes and Blood-vessels 123 

Tuft and Convoluted Tube 123 

Diagram of Malpighian Circulation 1 23 

Nerve-cells, 350 Diameters 1 28 

Bipolar Ner\'e-cell, 350 Diameters 128 

Multipolar Nerve* cell, 200 Diameters. . . 129 

Ganglion of a Mouse 129 

Ner\'ous System of Mollusca 1 30 

** " Radiata 130 

" " Articulata 130 

The Sympathetic Svstem 181 

Exterior of Bniin . .' 1 32 

Tlie Cerebrum 133 

Section of tiie Cerebrum 133 

Base of the Brain 134 

The Cerel)ellum 134 

Sections of Spinal Cord 135 

The Spinal Cord 13G 

Registering Ganglion 137 



Influential Ganglion ]38 

Simple Papillie, 35 Diameters HI 

Compound Papilhe, GO Diameters 141 

The Tongue ... 144 

Divisions of the Xasal Canity 1 45 

Distribution of Olfiictory on Septum of 

Nose .' 145 

Distribution of Olfactory on Outer Wall 

of Nasal Cavitv '. 145 

The Pinna '. 150 

Externad, Middle, and Internal Ear 150 

The Ossicles and Muscles 151 

Labyrinth magnified Two Diameters . . . 152 
Exterior of the Three Semicircular Ca- 
nals and Cochlea 152 

Membranous Libyrintb of the Canal. . . . 152 

Section of the Cochlea 153 

Distribution of Cochlear Nerve 1 53 

Spiracle of Insect 158 

The Vocal Cords 158 

Position of the Eyeball in the Orbital 

Caivity 168 

Blood-vessels of the Choroid Coat 169 

*• ** " *« if^ij 

The Eveball .'..!.'. 169 

View of the Crystalline Lens 170 

** ** 170 

ti ii ti i( 170 

Fibres of the Lens 170 

Vitreous Humor, showing the Hyaloid 

Membrane 1 70 

Muscles of the Eveball 171 

Cellular llssue. .' 176 

Adipose Tissue 1 77 

Skull of P^uropean 1 85 

Negro 185 

** Chimpansee 185 

*' Orang 185 

The lactometer 190 

The Pioscop 191 



Famtomt, physiology, and hygiene. 



Mu^h.'j^^-^'^ 



LECTURE I. 

NTRODUCTION. 






tthewies regarding the Ktititre of Life. — The Food introduted into the 

System 18 crnnbiiatibU. — 7'Ae Siibataiicea voided from the liody are all 

burnt or oxidized. — The Methods to be employed in the Exuminaliori 

> of the Structure and Function of Ort/anisma endotecd loilh Life. — CeUt 

' enter into the Coniponitiuii of nil 7'ieaues and Creatures. 

i What is Life ? Tlie pLilosophers of past times tell us tliat 
it in ail iulwrn, inherent power, by wliicli plants and animals 
resist for a time the decay and final oxidation or dtstniction 
[■to ivliieh they must sooner or later submit. 

The physiologist of the pi-esenE clay demonstrates, by espen- 
lents which ■^ve can not reftite, that the oxidation of the ma- 
tennis introduced into the system aa food is one of the essen- 
tial conditions for the maintenance of life. 

Uidess we breathe air, ttr some gas containing oxj'gen, de-ath 
is in a few moments the inevitable result. Without water, we 
may for a short time exist, tortured by an agonizing thii'st. 
Without food, life may be prolonged for two or three weeks, 
or even a month ; but starvation will have so weakened the 
powers of the sufferer that he is either reduced to a condition 
of hopeless delirium, or the hasty, careless inti-odnetion of food 
into the stomach will produce a shock fi'om which the system 
can not recover. 

If we submit the substances employed as food to chemical 
analyf^ifs, we find that they are, without exception, composed of 
carbon and hydrogen, to such an extent as to furnish a consid- 
erable amount of heat when burned in the air; they are there- 

loJcrn iJca of life? What ia Itio 



|2 TUEOUY OF LIFE. ^^^^^H 

fore, combustibl& If we examine in a similar manner tlie ma- 
terials fjected from the body, we find that tliey litive been 
more or less pei-fectly oxidized in the system, and yiidd but 
little heat when burned. 

From such facts as tliese, we conclude that the essential con- 
dition for the proper maintenance of life in man and animals is 
a sufficient supply of aii", water, and food. We may regard 
our.selves as uiacliines, in which power is produced by the oxi- 
dation of a certain quantity of combustible niaterial; and ns 
in a steam-engine, power is genei'ated by the combustion in 
the furnaces of tlie boiler, so in man, oxidations in nerve and 
muscle are absolutely necessary for the production of thought 
aixl action. 
^ Tiie decay and death of the tissues are essential to the exist- 
ence of the individual. The human maeliine we.irs away Iiy 
use, and num can not live but by the destruction and repru- 
diietiou of the cells of which the body is composed. 

Life, therefore, is not a condition of stability, a power pos- 
sessed by plants and animals of resisting the great ])hysiertl 
laws of nature; it is in accord witli them, and subject to their 
domination. Tlie wonderful enigiua of our esisti-nce h.is been 
beautifully expressed by one of the greatest of modern physi- 
ologistH, who says; "An on;;anlsm, no matter of what grade it 
may be, is only a temporary fonn, which myriads of jiarticles 
passing through a determinate career give rise to. It Is like 
the flame of a lamp, which presents tor a long time the sama 
asfiect, being ceaselessly fed as it ceaselessly wastes away.'' 

As we seek to explain the ordiaary phenomena with which 
' we come in contact l)y observation and ex]K'rimeiit, so in phvs- 
iologj' we should, as far as is expedient, endeavor to examine 
into the operations of the organs and glands of the body liy a 
careful study of their structure and action. If we fimi that cer- 
tain articles are conveyed to a manufactory, and in due eoui-se 
of time other materials of greatei- value are produwd, we inves- 
tigate the nature of the niiichinery and the materials used, and 
have no difficulty in uiideistjuiding the [troce^ses employed. So 
with any organ or gland, if we carefully examine its structure, 
the materials conveyed to it and lliur«e which it prtKlnces. we 
Boouer or later an-ive ut a rational explanation of its action 
and tiinction. 

Applying a similar system of investigation to living crea- 

WhBi snbsinnces ore rv 



ANATOMY OF CELLS. 3 

tures and the tissues composing them, we find, on submitting 
them to the test of the microscope, that they are constructed 
of cells, and fibres which originate in a cell, which is the sim- 
plest form of living organism, and invariably consists of certain 
parts, without regard to its function or the structure it may 
compose. 



LECTURE II. 

CELLS. 

Parts composing a Cell, — Vegetable and Animal Cells, — All living Things 
originate In and are composed of (Jells, — Reproduction of Cells. — For- 
mation of 7'issiies from Cells. — Secreting and protecting Cells. — Cells 
enter into the Composition of Liquids. — Nutrition of Cells. — Definitions 
of Analomy^ Physiology^ ajid Uygiefie. 

If a drop of blood from a frog be placed under a micro* 
scope, and examined with a suflBcient magnifying power, innu- 
merable minute elliptical objects will be seen, as represented 
in JFlff. 2. It is the duty of each of these particles to convey 
oxygen to all the organs, and enable them to perform their 
functions properly. 

^This minute microscopic body is called a cell. It consists of 
wan external membrane or cell wall, which incloses the cell con- 
tents. ^These may be either fluid or solid, depending upon the 
character of the cell. The defined separate mass contained in 
the interior is called the nucleus ; in it the changes to which 



Fig. 1. 





Cells showing Nuclei. 



What is the simplest form of living organism ? What are the parts of a cell ? What is 
A nucleas ? 



4 EEPRODUCnOX OF CELLS. 

the cell is liable usually commence. Sometimes the nucleus it- 
eelf contains a gi;rrainal spot, to which the name of nucleolus is 
given. 

The simplest example of animal as well as vegetable life is 
also a cell. Of this we may satistj- ourselves \>\ placing; uuJer 
the micmscope some of the greeu elimy material t-jiH'-l c«ji^ 
fcrva, which grows in stagnant %vater. At lirst we oiilv see 
the elongated cells which torm the tibres of the plant : but as 
we examine their various-ahaixni nuclei, we are stirprised Irdfa; 
time to time by cii-cular bodies which clash across the tieltlOT 
tile iustniiuent with great rapidity, and seem not only to jmjs- 
sivs thr i*ow.-r of voluntary motion, but also the capabilitv of 
dirtTtiiiir tlicir ri.ui'se iiit«> any desiivtl pattwi These ai-e mon - 
ad--*, or cell '* ^iidi>^Y.-d wiili v.bnit:^;^- motioii^ ihey ihei-efore 
belong to the animal kingdom, for the posse^^'ion of this power 
is the bestdistinguishing mmk l>etween a j)laat and an animal. 

K.vamining the genu trtuu which .iny given juiiuial origin- 
ates, \vi' find that it also in a nucleated cell. Since, tliei-etoi-e, 
all living things, whether they belong to the animal or vegeta- 
ble kingdom, oiiginate in ami are born from cells, we must re- 
gard these minute oigiuiisma with peculiar intei-est, and en- 
deavor to familiarize ouifelves with their various forms, and 
their methods of repi-oduction. 

r»* An excellent illu«tratii>ii of a simple ^-ell is otl'ered by an 
egg, in which tln^ slull lepnsents the cell wall, the white the 
cell contentjtlie yolk the nucleus, and the germinal spot of the 
yolk the inich'olus. 
In the eggs of some of the lower fonns of animal life we can 
at oiir leisure watch the development, growth, and final pixv 
j.,^ 3 duction of the pertect creatui-e almost 
- as easily as ive can trace similar opei- 
'M 1 (fi\\®^'^ 'H ations in vegetable cells. Ilie pi-o- 
cesses in both are the same, but since 
tim vegetable cells ofler fewer obstruc- 
tions to the use of the niieroscojK; in 
the study of their reproduction, we 
ihnll deal chiefly with them. 




^ flW ^ Cells are multiplied or reproduced 

^b / ("ither hy section or by granulation. 

In the first the cell wall gradually 



cpwdMU M of <;.ii. It sw.ion, fl oiil>k.s in toward the nucleus, f 



K 



Wlinl la lt> mmiHuiiiim ? Whni »« munnilKF Whm h iho i 
I * Ilium (inil nn nniniiil 7 Wlmt i< iho oriRiti of n plnnt or *i 
iirlBuTa call bjr Ihow af nn rgg? How Dm nilUirpnxiuocd? 



TISSVES AKE COJIPOSED OF CELLS. 




to give the cell a diimh-bell tbrni. \vliioh becomes by degrees 
more aod more corojilete, until it is finally dinded thi-ough the 
nucleus and twt) peifect cells produced, lu reiiroduetiou by 
granulation the movement commences in the nucleus. It breaks 
up into exceedingly minute grains, which form nucleoli, these 
gradually enlarge until they fill ,-... ._ 

the nucleus, wnich scnm disap- 
pears, and the cell seenin to be 
filled with nuclei The wall then 
bursts, and the nuclei, l>eing set 
free, become new, perfect cells. 

In order to form tissues, ei-lls 
are »ometimes arranged as in /'7y. 
5, presenting an appearance simi- 
lar to that of a ■wall built of cut 
, stone. Such are called mural tis- 
8ue.s. Sometimes cells are elon- 
gated and placed end to end, as in 
the fibres of the yeast j)lant and Munuiiuiit 

eonter\'a. In other instances the cells become greatlj' elonga' 





DIVISIONS OF I'HYSIOIX)GT. 




twl, as iu ill viiluntaiy niuwle and filtrous tissiiesi. If the celln 
retain their Ppherical figur« the 
oriraiir* foiTDetl jirodiice secretions, 
whilt; iu tlie skill ami all structures 
iuteiided iiiei-elv for pn>te<?tion, 
they dry up antf beeunie seale-likf. 
iVot only are tissues foiniK>sed 
of cells, but the animal fluids, aa 
for example Mood, contain one or 
more sjjeeial forms of cells by 
which we can often detect theu" 
presence. The descnption of these, 
as well as of the cfUs uf special 
tissues, as muscle anil nerve, must 
be reserved until we reach the dis- 
cussion of such fluids and organs. 

While a cell is, properly speaking, the simplest organism, 
there are lower forms which liave been placed in the animal 
kingdom ; among these ai-e the varieties of inouera, which ai-e 
mere minute particles of a mucous or jelly-like matter, called 
protopIasiH (which siguifies the first or simplest form of or- 
ganic mutter). These olgects are not possessed of definite 
organs, nor of sjiecial form, yet they play an important part 
iu the general scheme of life. We may, indeed, say that 
every uiiimid first appears as a minute speck of protoplasm, 
which becomes a cell, or an ovum, from which tlie fully devel- 
oped creature is produced. In the vegetable kingdom, also, 
protoplasm is of the utiuost impoitance, the active cells which 
form tlie tissues of plants generally having an iuterlor lining 
of this substance. 

Iu order that^a simple, organism like a cell shall exist and grow, 
it must be supplied with proper nutriment. The tissues of men 
and animals, being formed of cells, must therefore be furnished 
with the materials required for their growth and develojiment. 
To satisfy the stern necessity that Nature has thus impressed 
on all animals, that they should seek their food, she has merci- 
fully provided them with bodies constructed in such a manliei" 
aa to he cjipable of niotiou, and possessing tiie power uf con- 
verting various articles of food into a nutritious fluid, on which 
tissues may feed. 

The study of the body is divided into two distinct branches, 



a b llie OifTerencc belween n secreiing iiiiJ ft prorecring cell? Drwiibo i 
■ wotiifitiuim ? Into irlut bmncliei ii the uaily of the boijf diridMly 



TIBBUS8 AlfD OBGA-RB OP TITK BODY. 7 

Anatomy and Physiology. The first deals with its structure ; 
the second treats of the functions of the organs of which it is 
composed. To these we may add a third, Hygiene, which exam- 
ines into the conditions most favorable for the maintenance of 
perfect health. 

LECTURE III. 

THE HUMAN BODY. 

77i£ Tissues and Fluids composing the Body, — Divisions of the Body, — . 
Canities of the Head^ their Contents, — Cavities of the Tnmk and their 
Contents, — Subdivisions of the Extremities, — The Skeleton^ its Uses, — 
Composition of Bone,, and variations in the Proportions of its Ingredi- 
ents, — Diseases of Bone. — Imjyortance of Bones iti certain Manufac- 
tures. — Microscopic Appearance of Bone, — Membranes of Bone, — Di- 
vision and Classification of Bones. 

TirE body is composed of solid tissues or organs, and fluids. 
Tliey are, 

1st. Bone, which supports the other tissues and organs, and 
gives a fixed figure and form. 

2d. Ligament and cartilage connect the bones and form a 
skeleton, possessed of joints and capable of motion. 

3d. Muscle, endowed with the property of contractu it}', gives 
motion to the body. 

4th. Organs of nutrition, divided into digestive, absorptive, 
and circulatory. 

5th. Organs of secretion and excretion, as the lungs and kid- 
neys. 
^ 6th. Nervous tissue regulates the action of the muscles and 
all the organs of the body. 

7th. Special senses — vision, hearing, smell, taste, and touch — 
by which the system is brought in communication with exter- 
nal objects. 

8th. Areolar or connective tissue. 
9th. The skin and its appendages. 
10th. The organs of reproduction. 
^^The fluids of the system are, 

\f Ist. Bloodj which may be arterial or venous. The first is 
ybright red, owing to its containing oxygen ; while venous blood 
r is dark red, and contains carbonic acid. 

What is Anatomy? What is Physiology? What is Hygiene? Whnt are tlie tissues of 
the body? What are the uses of bone? of ligament and cartilage? of muscle? What are 
the organs of nutrition ? Give examples of the organs of excretion. What is the finiction 
of nervous tissue? Name the special senses. W^hat arc the fluids of the body? W^hat is 
rhe difference between arterial and venous blood? 



FLUIDS OF THE BODY. 



2(1. Chyme and chyh. The first Is a tawny yellow color, aad 
formed during digestion in the stomach. The second is milky, 
and is found in t!he small intestines and lacteals. 

3d. Z/ifmph, a colorless fluid, contained in minnte vestwla call- 
ed lymphatics. It represents the excess of nutriment conveyed 
to various parts of the lK>dy. 

4th. Bile, a yellow or greenish fluid secreted by the liver. 
It sometimes becomes condensed, and forms haixi masses called 
gall-stones, which cause excruciating pain as they pass into the 
mtestine. 

5th, Digestive hiives, consisting of saliva, gastric, pancreatic, 
and intestinal juiees. 

6tli. Kivn-fi'iiin and stvretio^ns, such as urine, sweat, milk. 

For the niike of convenience, the body is described under six 
divisions— head, trunk, and four extremities. 

The head contains the following cavities; 1st, The cranial, 
which accommotlates the brain ; 2d. The buccal, in which the 
tongue and teeth are placed ; 3d and 4th. The orbital, contain- 
ing the eyes : and, 5th. The nasal, inclosing the oman of smell. 

The tnmk is diWded into three cavities; 1st. The thoracic, 
which has yielding bony walls, and eontjuns the heart, lungs, 
great blood-vessels, and air-tubes; 2d, Tlie abdominal, sur- 
rounded by soft, yielding muscular ■walls, and Pt-parated from 
the thoracic by a muscle called the diaphragm (^-rigi. 43). 

The abdominal cavity contains the liver, which lies immedi* 
ately under the diaphragm, and chiefly on the right side; the 
stomjich, partly under the Hver and on the left side ; the spleen, 
on the left of the stomach; the kidneys, in the back of the 
cavity; the intestines, in front and on the sides; the pancreas, 
beneath and behind the stomach. 

The pelvic cavity, inclosed by unyielding bony walls, con- 
tains the bladder and rectum in the male, and the bladder, rec- 
tum, and uterus in the female. 

The extremities are divided into the upper and lower. The 
subdivisions of the npjjer extremities are the shoulder, arm, 
forearm, and hand. Thuse of the lower extremity are the hip, 
thigh, leg, and fotit. 

with these preliminary remarks i-egai-ding the general ehar- 

Wliot it llio diflercncD betwwn cliyme nnd chyle, an J where «re thej foiinil? What ii 
lvm|)h, nntl in whnt \et»W it it runnd? Whni ia bilef How nra gnll-slones rurmcd? 
Wlini nve iha dittcailvo juicca f Whnt nra the divisions of the bniSy P Whni enviiiu iirs 
round in the hcnd? Whni do they cniitoinf Nnmo the tnviiiw in'the irnnk. Whni nro 
Iho fonlents of the Ihorntnc:— nf tlip nhdomlnal — of the pelvic cnvily? What arc the enhdi- 
Ti&ions vf llic uppvr extremilj' ? o( Ihc lower e: 



FUNCTION OF TilE SKEl^TTON, 



acters of the tissues and fluids of the body, we now pass to the 
study of 

THE SKELETON. 

All aairaals are provided with a more or less perfect ekele- 
ton, the object of which is to furnish a support for the various 
eoft tissues and organs, or to protect them fioin injur)- and vio- 
lence. In the lower orders it is often placed on the outside of 
the body, and is the only protection the creature has aijainst 
the attacks of its numerous euemias. An excellent illui^tration 
of this arrangement is afforded by the oyster, which is funiisli- 

1 ed with a hard shell or exterior skeleton, the chief use of which 
ia to protect the soft tissues from injury. 

Passing a little higher in the scale, we find that the lobster 

I and such creatures are endowed with a far greater ft-eedom of 
motion than the oyster; consetjuently, though their skeletons 
are on the outside of the body, they are Innlt on a different 

L plan ; the various parts are lighter, and aiTanged so as to fur- 
nish a system of jointed levers and supports, I»y which the 
creature can at its will transport itself from one place tn anoth- 

I er, and avoid its enemies, or obtain the food necessaiy fctr its 

I proper nourishment. 

Though a certain degree of facility of motion can be reached 

I by means of an e.xteriov skeleton, yet it is almost incompatible 
with such perfect freedom as in retiuired in the higher animals ; 
consequently we find that in fishes, reptiles, bints, and beasts, 
the skeleton is in the interior of the liody. It is every where 
covered by soft tissues, and is arranged so as to fiimisli levei-s 

I for the organs of locomotion, or form cavities in which the 

I more delicate organs, as the brain, heart, hings, and digestive 
apparatus, may be pi()peily protected from injuiy. 

In man and animals, tlu^ sepai^ate pieces of which the skele- 

I ton is composed are called hon£n. These differ in their form so 

[ as to fulfill the purposes for which they are intended, t)ut in 

. chemical composititm they show but slight variation. 

A Bo/yjtis of Bant. 

Golntiiie , 83.171 , 

Blooil-vesseU I.ISi 

Photplute uriimc 

Ckrbonalo of limit 

Flnorido of caldam... 
Phosphnta of in 
Soda ealta 



■orBimit 33.a0 



Whrtt u iliG object of the ikcleion ? Ix 
*"«»re iisnsesinihe lii«her animali ? W 
<n of boiiu 1 



c bones? Whnt is 



CIIE-llIfAL COMPOSITION OF BONE. 

Examinins! the above analysis by Berzeliiis, we iiml that we 
lay ix'gard bone as being composed of aiiimal and niiiteral 

\ Bubstaiices in the ]>roiioition of one third of the foimer to 

[ about two thirdi* of the latter. This, although true m regard 
to bonew of adidtfi, is uot the ease in children and oUl peojtle. 

' In the tbnuer the jiroportiou of animal material is far greater 
than one third, and eonsetpiently iu infancy and early tliihl- 
hood the bones of the kiwer eJctrtsHities are apt to bend if they 
are used too soon, since they are not suflieiently eon^^olidated 
to sui>iK)rt the weight of the body. The age at wliieli they 
may with safety be used dejieuds to a great extent on the diet 
and digestive powei-s of the child. If the iood is not nutri- 
tioui*, or the constitution of the infant is poor, the jiroiiortion 
of animal material in the bones will be too great, and ihey will 
be flexible and bend, producing the deformity called rickets or 
bandy-legs, in whicli not only the bones of the legs, but also 
the nbs and pelvie bones, may lie deformed to such an extent 

• as to inteifeie .seriously with the proper performance of the 
functions of the body. 

In the osseous tissues of old people, on the eontrarj', the pro- 
portiou of mineral matter is in excess ; cousequeutiy their bones 
are veiy brittle, and break readily, often being fractured by 
Buch slight violence as making a false stej) while walking. 

' Not only does age affect the composition of bone, but Forae 
bones always contain a greater pi'opoil-ion of mineral substance 
than othei-8. For example, that in which the organ of hear- 
ing is situated possesses such a large proportion of inorganic 
substance as to liave received tlie mime of the pitrm/n, or stone- 
like bone. With these exceptions, we may regard bone &% 
having a unilbrm composition, represented by the ajialj&is of 
Berzelius. 

The presence of animal substances in bones may be readily 
demonstrated by burning them in a vessel ti-om which the air 
is excluded. Treated in this manner, they turn black ; tlie car- 
bon of the animal substance remaining, while the liydrogen 
and oxygen are diiven off. To the black residue obtained the 
name of animal ov bone charcoal is given ; it is of great value 
in certain manufactures, owing to the property it possesses of 
bleaching various oi^anic eoloiu It is extensively used in re- 
fining sugar ; the crude dark brown sugar being dissolved in 

What arc ihc pro|iorlioi» of aniinnl and mlncml nutKranrrrg in llirr bone* of ndnll*? Wlint 
BTO Ilie propordrinB in thiWren T What is mpunt hy rickets ? Wliiit ig thy compwiiior of 
Sonc in old pnranmt Wlikli bono aoiitaim the crfBlcH nnimmt of mincml subsinnce? 
Wlini a nnitnkl charconl ? Iluw is it jircpitrcU? What arc iia weet 



BONE UNDER THE MICROSCOPE 



(Pater to form a siniji, wLicIi is passed tlirtmgli a colurfin of 
!oardt;ly-iH)wdei'ed bone charcoal, twelve or fifteen feet in 
pength, ami escapes below as a colorless rtiiul, wliioh is evajxi- 



Kted aud c 



.allized i 



irket i 



I masses, and returned to tlie 
ished aud white sugar. 
If the hones are burnt in a current of air, they finally be- 
come perfectly white; the mineral material, consisting chiefly 
of phosphate of lime, alone remaining. The bone-earth pro- 
tdueed in this manner is in the form of powder used to make 
rupels for refining gold and silver; it is also cniployetl as a 
fertilizer. 

A very pretty methotl for separating the mineral from the 
Jdniraal materials is to jilace a bone in dilute hydrochlunc acid, 
wniposed of one part of acid to ten ur fifteen of water. In the 
!ourse of a few days the acid dissolves all the mineral sidt- 
stance, leaving the animal material, which preserves the origin- 
1 figure of the bone, but is so ile.\ible that it may be reatlily 
Jtied in a knot. The compo-^i- p,^ s 

■tiuii and growth of hones may 
Fbe satisfactorily stndied by the 
examination of their sectiims un- 
der the microscope. With a 
suitable iiower the appearance 

I in Fig, 8 IS obtained. The large 
bpemngs are called the liaver- 
^an canals, through which the 



larger blood - vessels pass to 
nourish the bone. 

In Fig. 9 the fine lines are 
called canaliculi. They trav- 
ei"3e tlie tissue in every direc- 
tion, and convey the fluid por- 
tions of the blood to the lacu- 
nw. or l)oiie cells wliicli are scat- 
tered throughout the fabric,and 

! rirllnina of »HEnr coniluclrd f Fur wlinl iMiriHue is honc-Bsli i'm|iloyi-il V 
pfitoh inKrciUpni n( innto ii whiMe in nciil ? What U ilic niipenrnncc of bone under tlio 
' eapt ? WiiBt nro tlie liaierrinn ciiiiul> > Wlinc nn> tbu Incunx ? 






CLASSIFICATION OF HONES. 

are represented in Fig. 9 liy the 
black masses. 

The development of bone 
first begins by the formation 
of a mass of cartilage which 
takes (in the figure of the 
bone. In this a variable nnm- 
l)er of sTKJts of true bone ejacl- 
ualiy apjjear which are centres 
of ossification. Around these the mineral matter is deposited 
until it extends thmiighout the mass, and it becomes perfectly 
consolidated, and possesses the rigidity necessary to adapt it 
to the purpose for which it is intended. 

AU bones are covered exteriorly by a membrane, in which 
the blood-vessels subdivide and foi-m minute arteries, which en- 
ter the haversian canals to nourish the osseous tissue. To it 
the name of periosteum is given ; and so necessary is this mem- 
brane to the well-being of the osseous tissue, that any injury to 
it results sooner or later in the death of the bone. 

For convenience of description, bones are divided into three 
classes, long, flat, and irregular. The first are found in the ex- 
tremities. They consist of a shaft composed of hard, dense tis- 
sue, usiially hollow, and filled mth manow or fat. The cavity 
is cyliiidricid in H]iit]u', and lined Avitli .1 membrane similar to 
the 1 1'; ri- ■st ■ -1 1 11 i_A*Jt "h < ■; 1 II i;^l \\w I'li d 1 )s t < I'U l U i*** duties are the 
sameairrnosiTi ilV bre^Ten^^ ends of (belong 

bones are smooth, and enlai^ei:! to furnish surfaces suitable 
for the tbrmation of firm joints. The canal of the shaft does 
not e.vtend to the ends of the bone, but disappears in a spe- 
eies of cellular Btructure, which is lietter adapted to the con- 
ditions which are to be fulfilled by the extremities. 

Tlie flat and iri'egulai' bones usually incloMC cavities, and are 
found in the skull, pelvis, and other regions. They are com- 
posed of two layere of hard, dense tissue, the intermediate space 
being occupied by ajjougy tissue, thus combining strength with 
lightness, as is also the ease \ntli the ends of long bones, 

Bone, like the other tissues of the body, is subject to a num- 
ber of diseases, such as cancer and inflammation, but the spe- 
cial trouble is the liability to fracture. AVhen a bone is bro- 
ken, if the fractured extremities are kept projwrly injuxtaposl- 

llnw Arm llin (icvrlopmcni of bone Mimmercc? Whntis iho pcriosioiini? Wlmt nre llio 
llinus cIsMm or bones ? Dcecrilie n lout: lionc, Whnt is llto cndoEilconi ? How far (lom 
tlio cwinl of n long bone exleml ? Whm is ihe diffoirnco in siructure bclwecn ihc slmfl iind 
' 'a ofu long bone? Haw arc flat bones conuraciod? 



THE SKELETON. 15 

tion, they unite in a few days hy tlie formation of cartilage, in 
which the mineral matter is gradually deposited, until, after the 
lapse of a few Aveeks, the juncture becomes more solid and 
dense than any other part. 

In the Hunterian Museum there are many singular examples 
of diseased skulls, some being an inch thick, and others pos- 
sessing? osseous growths from various parts. In one Avhich be- 
longed to a prize-fighter, there are osseous projections from the 
rim of the orbits about three inches in length, which were pro- 
duced by injuries received in various encountei's. 



LECTURE IV. 

THE SKELETON. 
JStimber of JBonea in the Body, — Bones of the Trunk, — Pelvic Bones, 

The number of bones in the body varies at different ages, 
but in the adult there are 238. They may be conveniently 
studied under the following divisions : 

t;, „ (Cranial S 

^''"" 'jKace U 

m y, i Xi'ck, tlionix, and ulKldincii r>0 

( rclvis 4 

upper extremities - t Jc, h C4 

Lower cxti-cmities -■ J Yt [" ••• ^^ 

Intcmnl car (J 

Teeth j$2 

The bones of the skull are divided into those of the cranium, 
which inclose the ca\aty in which the brain is placed, and those 
of the tace. The latter are very in*egular, while the former are 
true flat bones. 

^The cranudboiie^ are the frontal, occipital, sphenoid, ethmoid, 
nwo temporal, and two parietal. 

■ The frontal forms the forehead and the roof of the orlntal 
cavities, in which the eyes are placed. 

The occipital (jP'if/. 12) forms the })ack of the head and 
part of the base of the skull. The large opening is the fora- 
men magnum, through which the spinal cord passes. 

The siyherioid {^Fig. 13) bears some resemblance to a bat, be- 
llow is the fracture of l)oncs repaired? How many bones arc there in tlic l»ody? How 
many in each division ? Name the cranial bones, liescribc the frontal, occipital, sphenoid 
bones. 




ing A'ery irregular in form. It articulates with nearly all L 
boues of the skull, and forms the keystw 
to the arches of the eranimn. 

The ethmoid {Fuj. 14) lies between the 
cninium and the face. It is comjxtscil of ji 
iHimhf r of very thin plates of iKine, rolled 
into a mais of scroll-work, and covered Ijy 
nmcous membrane, in vvltit-lt the filuinents 
^ ^ ' of the olfactory nerve terminate to tbrm the 

The EiUiurfd Bona ,, ,,•' 

oraan ot smell. 





The tet)>poral hoiie^ aid in forniint; the base and sides of tlj 
skull. Tliey are described a-s being conijMJsed of three part| 
the mastoitf, thick and cellular ; the squamous, very thin as^ 
brittle; and the petrous, dense, hard, pyramidal in shape, an 
hoHowed out in the interior into irregular cavities, which eo 
tain the small aufHtorj' lionen. The sense of hearing is lotlffji 
in this part, the waves of sound reaching the interior caviti 
through an opening on the out8i<le, called the meatus audit 

DcBcrilio the ethmoid and Icroporal bonca. 



BONES Of THE FACE. 



I 



riua extemus, while the auditory nerve gains access to the same 
cavities through an opening near the njx?.\ of the petrous part 
called the meatus interniis. The projecting ami of bone is 
called the zygoma, and the smooth gle- ^ ,.|g „ 
noid cavity at its origin articulates with 
the lower jaw. 

The pan'ftal honeH are quadrilateral 
in shape, and form tlie sides and i-oof of 
the skull, The inner surface is gmoved 
ty arteries {Fig. 17), the nipture of 
■which is one of the serious eousequeneea 
of fi'acture of the skull. 

The bones of the tace are three max- 
_-, two nasal, two palate, two malar, 
lachrymal, two tvn'Iiinated, and one vomer. 



/' The 

/illary, t 
I twp lac 





Uiperlor MuxHIii 
ktwr Siirfna. 



There are two bones in the upper, and one in the lower jaw. 
The Hpj)er ma.\illaries form the floor of the orbital cavities, and 
present a number of projetitions, the most important of which 
are the alveolar jiroce.'is, in \vlueh the teeth aiv fi.\ed ; the pal- 
atal, which forms part of the liard palate ; and the nasal, which 
forms the side of tlie nasal cavity. Tlie body of the superior 
maxillary presents a large cavity called the antrum or cave, the 
object of 'whieh is to give resonance to the voice. 
The lower maxillary none consists of a horizontal 
and ascending ])ortion ; the ends are smooth, to ar- 
ticulate with the temporal lione, while the teeth 
are fixed into the alveolar jiitjcess of the hoi-izontal 
lortion. 

The TUisal honts form the upjier hard part of the "^ ^""i ^ 



Fit 

I 



I WhM M iho (jBomi ? Wliiil is ilic nnme of ilio unit 
' ' nl of the icmponi! bone? Wlint U iho HlinpG m 
•re the bones of tbc face? DoKribe iFip n|ipcr it 
Dcrcribo Ihc loner mnxillnry bone. Wlicrc nrc 



Inr fnvirj? Whnt nrc Ilie ihree 
jAOsition of tho pHricliil lionei? 
nillnrv bonc". Wlml u tlie mi- 
ic n[u:il bones? 



18 



DIVISIONS OF THE VERTEUR-E. 



They afl 



The jKiIate honea are Blmped like tlie letter L. 
in fovming the hard jialate. 

The iiiiikirH tbriii the outer part of the orbital cavities, an 
the upper hiinl ]iait of the eheekfi. 

The hichriiiiuilx are small and rerj- thin. TJiey form a po 
tion of the inner side of the orbits, and are in eoiitact with tli 
nasal processes of the upper niaxillai-y. 

The turhhutted hoiita are in the nasal cavity, and attached t 
the ethmoid, in order to increase the surface on wliicli the '" 
tory nerve is spread. 




Tlie vomer is shaped like a plow-shai'e, and divides tlie 
sal cavity into two equal lateral jiortions. 

The bones of tlie tnmk are the o8 hyoides, twenty-four vept« 
bra-, twenty-four libs, the sternum, two ossa inuominata, the 
cnuu, anil the coccyx. 

'J'he us hi/oldt!H is situated in the throat, at tlie base of 
tonfjtie. 

Ilie t^ertebrCB are divided into three classes, seven cervical 
twelve dorsal, and five lumbar. The cervical are the smallest 



I 




and are in the neck ; the lumbar are the largest, and fonn the 

DeKTibo ihe polute bonn. Where art tike mnlnr bono ? Docrilie the Inf lirrmnl bon«a] 
Iho liirliinHUxl honn ; ih« vomer. Name tbn banes of llio tninli. Where in ihc o« hroii'^" 
WhnI nrc (ho diviwonaor iho venohric, and hoir mnny In cneh? In wlinl iwrt of the vi 
brd cobimn «ra tha brgrat bones foiinit ? 



,roM 



I 



THE VERTEBIEAL CULl'MN. ID 

email of the liack; the dorsal akl in fomiing the back oftlif 
chest, anil they all possess iact-ts on tlie sides, by which they 
articulate with the ribs. 

Each vei'tebra consists of a body, and incloses au opening,' 
through \vliich tlie spinal cord passes. Tlie ring of Ijone of 
each vertebra that forms this opening terminates p, „^ 

posteriorly in a sharp projection called tlie Pjn- 
nons pmcess. The vertebr* are an-anged one 
over another, and joined by ligaments and an in- 
tervening disc of elastic cartilage, so as to form a 
columu, marked in the back by the row of rough 
projecting spinous processes. Between the verte- 
bi"fe thei-e ai-e openmga through Avhich the spinal 
nerves pass. 

Considered as a unit, the vertebral column 
irni9 a sei'ies of curves : one in the neck, the 
lUvcKity of which looks forward ; one in the 
;e3t, the eonve.\ity looking backward ; one in 
le abdomen, witli the convexity fonvard; and 
me in the pelvis, formed by the sacrum and coc- 
byx, with the convexity backward. 

These curves, and numerous vertebrae with 
leir connecting cartilages, give to the column 
'great elastieitj', which protects the brain from in- 
jury by the sudden jars it would otlierwisi- be 
subjected to in jumping and such violent move- 
ments. The lower part of the column is support- 
ed by the bones of the pelvis and legs, and in its 
turu gives support to the organs of ttie tnmk, up- 
:r extremities, and head. 

The rifis aiv. about half an inch in ^vidth, and 
irved upon themselves so as to tbrm an m-e of a 
<nrcle. One of the extremities is round and 
smooth, to articulate with one or two vertebra-; 
the other is i-ough, and gives attachment to a car- 
tilage, by means of which the libs aie connected 
to the sternum. The under edge of each rib is 
marked by a groove, in which the arteries of the 
id are protected ti"om violence so jier- 
rtly that they are not readily reached in any ordi 



^DHcribo a vcncbin. How iirc iIid vprivlim connortcd? DcMrilic the rurrrn of the 
sbral (vlumn. Uow U ilio lower ]>iirt of ihe vcnchml ralnmii f.ii[>portF<l ? Describe 
How do Iticir cxircmtljct diRlT? How nro ihc ni'tcrics uf llic cliont jn'olcclcd? 



20 



THE PELVIC BOXES. 




by a knift'. Tlie seven tipper ribs on each side aiv called tr^ 

and the five lower false ribs. 

The sternum or }ireast-bone is flat, and connected with 1_ 

libs by costal caitilagea; it aiticiilates above with the clijj 
cles (Mg. 11). 

The Offm inumniucita, so calle< 
I'lum tlieir want of Rsciiiblance t" 
liny other Jcnown natural olijfct, 
jii'e eoniijosed in infancy of tlii« 
parts, which become consolidate 
into one bone in adults. ThCT 
are called the ilium, ischium, ana 
pubea. The first is tlie flaring por- 
tion, which forms tlie hij) bone; 
the second is the lowest part, an" 
terminates below in a i-oiigh \ 
called the tubei-osity, which be( 
the weight of the body when in 

the sitting ijositloii ; the thiid is the anterior portion. 

The jmluc bones unite in front to form an arch called the 

])ubic arch, which is nmcli more obtii.'<e in the female tljan in 

the male. The three divisions of the iniiunitnatuin meet in a 

smootli circular depression called the acetalmluni, which aceoni- 
Ki^ .„ modates the head of the femur to form the hi 

The sacrum is triangular in shape, and ai 
ulatea laterally with the ossa innomini ' 
above with the last lumbar vertebra, and 
low with the coccyx. It forms the postei 
wall of the jk-IvIc cavity, and is jieiforated " 
its anteiiiM- and jrostenor surfaces with a nu 
her of fmamina or openings, tlnnugli which tl 
terminal divisions of the spinal cord pass. 

■■ The coccyx is a small triangular bone a 

ed to the tip of the sacrum; it is the termination of the vei 
bral colunni. 

The ossa innoininatn, sacrum, and croeej'x form the pelvis, 1 
shape of «hich varies with the sex, In the male it is ei 
shaped, while in the fenial« the iliae bones flare out bo as 
give it more the form of a saucer, and the cavity is wider in 
Its dime nsions. an<l not so deep as ju tin- mal e. 

[low tnnnv ttiiu mxl (A'k HIw? Di-'hcHIic ilit iti'miiiu. IVtcrrliv ilic »*sn innomlil 
WliKL nrc ilie ilii-ioiiina nf ilic im innonilnniiim f WIihI i: 
ucclu bill urn ? Dcwrilic ilie Mcniin. Dcacrilio ibo dwryx. 




BONES OF THE UPPER EXTREMITY. 



LECTURE V. 



EXTHEJIITIES AND JOINTS, 



fc' 



teofifs oflhe Upper J^xIremHij. — lionea n/c/ie Zofer Eftitmity. — ViiHe- 
tita (^ JointH.^TUmes lehiefi. enter into the Cvnijw/u'lion i^ Joiiiln. — 
JuinU and Bones form Lvcers. — Diseases ami Wtiwids nf Joints. 

The houes of the upiwr estremitits ai-e the scapula, clavicle, 
r'humerus, radius, ulna, eight cai'pa], five metacarpal, and four- 
Fig.!a teen phalanges. 

Tlie saqnilti, or should er-h lade, is held in 
position by luuscles which are attached to the 
vertelH'ffi and ribs so 

that it is movable. ^p„_.^ Vk 

It is triangular in o^^*^^^— ^^^^iv i 
shape, the upper and Thpo.. 

outer angle tnraish- 
ing an articidur sui-face calleil the 
glenoid cavity, which receives the 
head of the arm bone to foiiu the 
shoidder-joint. 

The chii-'icl-e is shaped like the 
commonly known as the collar 
bone: its duty is to keep the shoulder-joint out- . 
ward and bat'kward. It is the fii-st bone in the Tv 
body that is jierfectly ossilied. 

Tiie /iii7ttemn, or bone of the arm, is a long bone, 
are all the rest of the bones of the upjier ex- 
mity except the carpal llie u]iper part is call- 
id the head ; it articulates with the glenoid cav- 
ity of the scapula. On the outer side of the head 
there is a rough mass called the tuberof;ity, to 
which some of the muscles that move the unu are 
attached. The lower end of the bone is grtiovi-d, 
foniiing a hinge-like joint ^nth the bones of the 
" >re-arm. 

The radius and vJna are the bones of the fore- 
The ulna forms the elbow-joint, wJiile the 



I The SctpntL 

Battel- f. It 



kWhat STC till! bones of the iippRr extreniilv? UpBciibc llie Bcn| 
Willi wlint cuTity doc* llic humerus arlicululc i" Whnl ai 
Which joint Joes Ilia ulnn cbicHy furm ? 



: tEie bouos of (be Tore- 



BONKS OF TIIK LOWKK tlSTHKMITT. 



radius forms the wrist. Tliey ai-e plai-ed side by 8ide,an3 

ranged so that the radiii3 can move to a («i-taiu extent ara 

the ulna, aud^ve to the hand the movement of rotatiod 

possesses. (^Fi^- 1 !■) 

The hones of the wrist, or carpal, f/tnies, are eight in niuuq 

and placed in two i^ows, the fij'st containing the scaphoid, sem 

ilunar, oimeifonn, nnd pisiibrm ; the second the trapeziiuu, tra 

pezoides, magnum, and uncifoi-ni. 

The mfhtrarpa/ hmif-H ai-e five in number, one for each finger 

they artit'uljitc uitli the second row of cai"pal bones, and fom 

the pahn of tlie liand. 

There are itmYt^itin phalanges, three for each finger and 1 

for the thumb. 

Tlie lower exti'emity is cotniiosed of the femur, patella, titt 

filiida, seven tai-s;il five metatarsal bones, and ibiirteea \ 
hinges. They all belong to I 
order of long bones. _ 

Tl]e/«H!/r, or thigh bone, ha: 
the head set on the shaft 1>\ 
means of a neck, which fonu 
an angle that vaiies with tin 
age of the individual In ok 
age the angle is nearly ninetj 
degrees, and coiisi-qucntly thi 
neck of the femur supports thi 
weight of the limly in the niosi 
disadvantageuu:^ manner, and ii 
very liable to undergo ft-actnre 
The ujiper part of tlie bone i 
furnished with a strong, rougl 
tuberosity for the altachmeni 
of muscles. The lower end ii 
expanded so as to form ■ 
condyles, separated by a dtfj 
gi-oove ; it m-ticulates with 1* 
tibia to form the knee-Joint. 

The iihia andjihvla form tli< 
leg. Tliey are elosely liounc 

together, and are not movalile like the Imnes of the tore-arm 

Wliit;1i lines llio riuliiiB form? How tnntiy liono ore tlicrc in tlio cnrjins? Komi 
tlicm. Ilow mnny mctacarpnl bones nrc ilicrc? Umr mnny pLitlRni^^H nre ilivrc? Nnim 
tho hnncs of llio lower extiTmiij'. Describe ihe femur. How Aoe* ihe nnBle of the «liaf 
unil nvek vary wiib ar,ai Vr'linl nrc ihebonoiof tbo leg? Whni ora ibcir rclaiioix Id tlji 
kriw iinil nnhlejoinu? 




J 



C03IP0SITI0N OK JOINTS. 



23 



^They I 



I 

I 
1. 

m 



i called malleoli, wliich j 



Tlie first fon 



terminate helow in p 
mness to th« ankle-juint. 

The patdla lies in fiout of and protects the knee-joint. It 
is inclosed iii the tendon of the muscles of the thigh, and ena- 
Wes them to act to f^reater advantage. 

Tlie tarsal bones are arranged in Uvu 
iBists of the astragalus, which ar- 
^ticulates with the bones of the 
le" to form the ankle, and the us 
UL-is, which forms the heel. The 
seconil row is composed of the 
ciihoid, scaphoid, and three cnnei- 
fbrm liimes. 

The metataiwin consists of five 
bones, one for each toe. They 
form the sole of the foot. 

There are fouiteen phalnn'jff, 
lliree for each toe, except the large 
,toe, Avhich li:w two. 

The bones of tlie internal ear 
M-ill be described in connection 
Avith the sense of hearing. 

The teeth belong pitiperly tn 

the function of digestion, and will be studied in connection 
■with it. 

TlIE JOINTS. 

Bones are united together so as to form either immovalde or 

movable joints. The Tiest example of the fii-st class is finnish- 

led by the sknll. In it the vanous Iwmes are dovetailed into 

leh other along their edges, to foiiii [)eifectly unyielding joints 

\lled mtiii-eM, wliich may be broken, and the bones obtained 

FBeparately, liy filling the tTanial cavity with well-dried peas, 

land adding wat'-r, when the peas swell and foive the bones 

ftfipai-t. The joints i>f the second cla-ss vary greatly in the de- 

jree of luobdity they [lossess, fi'om the sliding motion of the 

Rones of the carpus on each other, to the hinge-like motion of 

Hlie knee or elbow, or the aluiost nnivei'sal mobility of the bull 

and socket joints of the hi)j and shoulder. 

The tissues wliicli enter inti> tlie formation of a movable 
joint are, 1st. The smooth articular end.s of the bones; 2d. A 

Describe ilic pntclln. Nnmu iliu tni'mil iHintr.". Unw mniir mctntur«n1 bones nod p^n- 
' ngei are tliorc ? Describe liio (wo i-ntieiicii of jnini>, nnil gii-c example* of euli. Wbst 
vSBtBTOi? Wliat lisEiicscDtcr into the funnaiiun uFn joint? 




CLASSIFICATION OF JOINTS. 

c-oveiing of verj' dense jwlislied cartilage, which give* a fulifi^ht 
degree uf elasticity, ami rnds lu rediiciiig the frictiou; -Id. Liga- 
mcuts, which bind the bones together : 4th. The eynoviitl mem- 
brane or sac, which contains tlie iiiiid, and lies lietwecn the 
cartilages of the joint, its ohject being to i-ediice the fiiction ; 
ijth. Muscles, whicli move the bones; and, 6th. Nerves, which 
govei'ii and regnlate the actions of the muscles. 

i-^j aa The osseous tissue has alrendy 

been described. Cartilage conniste 
of cells and fil):'ous tissue. Liga- 
ment is composed of white fibrous 
tissue, in which the cells have be- 
come elongated into mere lines; it 
I is admirably adapted to the jnu*- 
! posefor which it is employed, flie 
synovial sac is also compuscd of 
fibrous tissue, and lined with se- 
nilis menil)rane. 'lliese are the es- 
sential tissues «-'f the joint; the 
muscles and nen'es are aiuxiliary. 
BuouLintioiT. -^y-g may t}ierefure pass at once to 

the study of the joints, and then take up the examination of 
the muscidar and nervous tissues. 

All the long bones, and some of the bones of the other clasfr 
cs, are used in the construction of movable joints, serving eltlier 
as levers to move the Itody, or to cai'ry on st»me process necc* 
saiy to the well-being of the system, as, for example, mastica- 
tion. There are three classes of levers, all of which are repre- 



I 





sented in the body. In the first class, the fulcnim is betweeaj 
the power and the resistance; in the second, the i-esistanee Jft 




COMPOSITION OP JIU3CLE. 



Bin the centre; and in the third the jxiwer is in the middle. 
I the aystems of levers in the tnKly, the fuh-riini is the juiut 

(pml the power the iiuiscle. In tiir 
we have iin exauiple uf a h-vrv >>[' i]\ 
l>odv on tip-toe Vve hav e an i\;iiiii 



bhiij. 
JoinI 



!-.: in n.i-lii^tli 
r M'r,)n<i; and.! 
II i -\iini[ih- ct til 



• lialtle to inflani 



Joints, like the other parts 'il' 1 1: 
mation. When the ligaments are involved, it i>t called rlieuma- 
ti«n ; this sometimes passes into a chmuic state, and is exceed- 
ingly painful. When the synovial membrane and cai-tilages 
ai*e mvolved, it is called white sivelling, which is very apt to 
terminate in a nnion of the bones and entil'eloss of the use of 
the joint. Sometimes small hard cartilages are formed in the 
knee-joint, which .'ilip between the ends of the bones in walk- 
ing, and produce the mo.st excruciating pain. Wounds of the 
large joints, though they may appear to l)e insignificant, are 



LECTURE VI. 

THE MUSCULAR SYSTEM. 



■ '" 

^■m! 






The Muscular Tissue. — Microscopic Characters of voluntary and involun- 
tary JIusele Cells. — Tendons and their position. — Divisions of Muscles. 
— Muscles of the Head and Aeci. — Of the Upper Extremities. — Of the 
Trwtic. — Of the Lower Extremities. 

TuE muscular tissue forms the bulk of the body; it is very 
freely supplied with blood-vessels, and is of a deep red color 
in the majority of animals, forming the lean meat or flesh — 
an excellent example being the beef prepared for sale in the 
limarkets. There are, however, exceptions to the general law, 
II the breasts of fowls, where it is white. TTie chemical 
elements entering into the composition of this tissue are c^t 
bon, hydrogen , oxy pen. nitro gen, and sulpl iur.: it is conse- 
quently li nurogenized boJy ; it also possesses the power of 
contractility, which is in part due to the manner in which it 

constructed. 



iddsgIb? V 





SlripedUi 

Must'les nifty be classififtl under two lifads : the voluntary, 
controlled by the will, as the miiflcles of the extremities; nnd 
the involuntor)', which act indepeiuleiitly ot' the will, and even 
without its linowledge, as the inusonlar c()at of the stomach 
and intestines. The mieroseopic characters of the two vniie- 
ties ai'e veiy different, voUmtaiy muscle fibre being lomposed 
of rectangular-shai)ed cells, placed end to end like the cells of 
conferva, and havini; a rectangular nucleus. The fibres are 

Fig, 40. 



fonned into bundles, the arrange- 
ment of the cells being such that 
the nuclei aie side l>v wide, and 
fomi lines. Owing to this pe- 
cidiaiity, it is often cidled striped 
muscle. 

Involuntary fibre, on the eon- 
trjirv, U <'oni|>osed of elonefatecl 
fvlls, and there is no special sys- 
tem in their iin'iingement ; conse- 
quently, the nuclei do not form 
lines, and it passes under the 
designation of unstriped muscle. 

Tlie force generated by the 



Viutripci] MoMto. 



nvulunlnry muscles, nnd iho cell* 



MUSCLES OK HEAD AND NECK. 



21) 



I 

I 

I 

I 



contraction of muscular fibre is applied to the bones tlmmgh 
the intervention of an inelastic band of white fibrous tissue 
called tendon. One extivniity of eaeh fibre of a niusele usual- 
ly anses directly from a lioue, and tlie other tenninates in tlie 
tendon, which passes over one or more joints, and is attached 
to another hone. The tendon Is sometimes on the side of the 
muscle, giving an ajipearance sitnilur to that afforded by an oi-- 
dinary quill pt-n. These are called pennifonn. S<mietinies 
fibres I>ranch off from both sides of the tendon; sucli are hipeii- 
iiifonn. lu some muscles the fibres radiate ft'oni a central 
point, as in the iris of the eye ; the.^e are called rudhite. 

It is impossible, within the circumscribed limits of a text- 
book, to describe all the muscles of the body; but it is desira- 
ble that every educated pei-son should know something regard- 
ing the names, position, and shape of the external nmsi'les, 
Iwhich ai-e situated immediately under the skin, and give to 
the body its beautiful contour and gi-acefully curved outline. 
Painter.i and sculptor;* endeavor to repi'esent tliem in vanous 
works of art, and every one takes an honest pri<Ie in develojv 
ing and exhibiting a gmceful muscular limb. 

The voluntary muscles may be described under six divisions, 
those of the head and neck, of the trunk, and the four extrem 
itiesi. The ends of the muscles are spoken of as the orj yin and 
jnayi^jjlj: the first is the portion in which the muscular Htn'es 
attached directly to the bone; the insertion is the tendin- 
ous end ; it is usually attached to the most movable bone. 

The muscles of the head and neck are the occipito-ti-on talis, 
■which lies immediately under the hairy scalp, extending from 
the eyebrows to the back of the head. Some pei-sons jjossess 
the power of monng this muscle to a veiy wmsiderable deirree. 
Two muscles, the temporal and masseter, arise fri)iii the tem- 
poral fossa on the side of the skull, ami are insertet] into the 
ascending portion of the lower jaw; they give motion to the 
jaw, and are emphtyed in the act of mastication. The cheeks 
are formed of a mtiscle called the buccinator. Tlie muscle that 
forms the lips is the orbicularis oris; it is employed in the act 
of kissinw, and consists of a number of circular liands tliat pass 
wound tne mouth, A similar circular muscle surrounds each 
of the eyes; it is called the orbicularis palpebrarum. The' 
t muscle that forms the nape of the neck is the trapezius; 

i« iho force cpncrrticil by musclii njijiliKil 7 Wtmi is /i |iemiifiirm inii9cle~hif«niii- 
— radiato? Wlicro nnt llio Inrgest masclcs fauncl? WJiBt nro tlic iliri.iinns of tsmi.' 
' Wbntiii iliEorii;i[i of n muscle? What in iti iruertion? What are the muaclc* of 
end aiiil neck? Docriba their ndions. 



ao 



MU'SCLES 01' EXTREMITIES AND TRUNK. 



it tliTOMH the head back ; it is opposed by tbe Rterno-cJeido- 
niastitiil iniiHcle, which bends the head fin-ward on the chest 
When I)uth sets of umsc-Ies at-t together, the head is kept firm- 
ly fixed, an in cttrryint; bnvden^. There are many other miis- 
wn in the head and iiwk, Imt tliese are the most pmminent 
and can Ije trawd in the majority of paintings or i)ieoes of 
Hculptnre. 

'file nniseles of the upper extremities are the deltoid, tri- 
nni<'.]hir fJiaiHjd.and coveiing the sbonhler; it raises the arm 
from the side of tliu body to a horizoiitiil iiosition. The trajie- 
ziua aids in carrying it np to the vertical line. The bicepti, or 
large ninsfle on the front of the ann, ilexes tbe Ibi-e-arm on the 
anu, and iiiakeB tlie ]trej)aration for striking a blow. Tlie tri- 
eejis extends the foiv-ann on the arm; it is on the back of the 
humeruK, and in useil in delivering a blow. The museles of 
the fore-ann are all small, an<l do not give any special marks 
or contom*, excej)t in pei-sons in whom the muscular system is 
exceedingly well developed; we must therefore leave the dt^ 
scription of tliem to inoii' extended works on anatomy. 

Ihe muscles of the tnmk are the pectoralis m^or and mi- 
noi'. They fomi the breasts, and, taking their origin from the 
sternum and inner edges of the ui)per lilis, are inserted into 
the Lumerns; they are employed in folding the anus across 
the chest. Opposed in action to the pectorals is the latJssiimis 
dorsi, which, ansing from the lower two thirds of the vertebral 
column, is inserted into the hunienis, and throws the arms 
backwai-d ; they are greatly develoin'il liy the exeivise of i-ow- 
ing. The muscle which extends ff.nn the lower part of the 
steiTiuni to the pelvis is called the rectus abdiniiinalis. As is 
the case with nearly all the muscles of which we have ti-eat«d, 
it is one of a pair ; ^vith its fellow it forms the anterior wall of 
the abdomen ; it is divided transvei-sely into thi-ee poitions, 
the divisions being well marked only in very nmscnlar indi- 
viduals. The muscles A\'hich complete the ^valls of the abdom- 
inal cavity are the obliquus extenius, obliquus internns, and 
transvei-salis. The filtres of these muscles are an-anged, as their 
names indicate, so as to cross each other, and jiroilnce in their 
action an e(^|uable pressure on the oi^ns contained in the ab- 
dominal cavitv. Ii! ;iilililion to these, there ai-e a LTeat num- 
ber of small iiiu-rle- id ilii. back and between the ribs; the lat- 
ter are called inlei(n~nil~ ; they ;iid in cairyinij: nn res] " 

ircriiily ? IJcwribc iheir in 



MUSCLES OF THE LO\VEK EXTREMITV. 



r 

^^■^ muscles of the lf>wer extivmities are, 1st. Those which 
^^^B the buttocks; they are called tin; glutei muscles. They 
Iffe an'anged in three layers, viz., exttTiiJil, middle, mid internal 
Though these muscles exist in the Inwer animals, they ai-e de- 
veloped til a far greatei* extent in iiuiii, iciving to him the ijow- 
er of retaining the erect, pcisition. Opposed to the clntei are 
the iliay and psoas muscles, which arise fivm the andominal 
surface of the vertebral colunin, nud, passing over the pubic 
'1»ne, are inserted into the femur, Tlie great muscles of the 
ifajgh ai-e the rectus femoris, which jjii^wes from the iliac bone 
to the patella; the vastus extenius and vastus internus, which 
^^take their origin from the outer and inner surfaces of the fe- 
•Ittur, and are inserted into the ]iatelh\ ; they extend the leg 
(*)a the thigli. The muscle which lanis ot>liquely across the 
'tlngh, from the iliac bone to the inner edge of the tibia, is call- 
fid the-fell orws, OT tailors' m uscle , sintc it is employed in bend- 
ing the lower extremities into the i)(.)sitiim assumed by pei'sons 
of tlint trade while at their work. The muscles that ai'e iu- 
'<erted into the patella are in reality attached to the tibia, for 
Ur& Btl-on^ ligament, about two inches in length, passes from the 
lower edge of the patella, and is attached to a mugh surface on 
...ytiie anterior edge of the tibia. The largest muscle on the back 
■T-, of the thigh is the biceps ; it flexes the leg on the thigh, and, 
^^/iince it takes its origin in part from the ischium, also aids in 
vji; "extending the thigh on the trunk. Tlie muscles of the leg are 
■i; ,;tiie gasti-ocnemius, on the back of the leg, giving it its fuU- 
•,-':lie88; it extends the foot on the leg, and raises the body in 
' ' 'walking. The tibialis anticus, and other smaller muscles on 
the fi-ont of the leg, flex the foot on the leg, and oppose the 
gastrocnemius. 

The involuntary muscles will be described together with the 
organs and functions with which they are connected. 

Wlint miiicle* tiimi ihe bullocks, nnd hoir nre iliey m iiiii)'eiJ ? Desrrilw tli<: nuiscles op- 
poiing ihe gliiiei. Describo tlie miuiclGs of the Uiig\t mid iheir ncliaii. Deiicribi! ilie mutclet 
of the lec oiid ibeir nclioo. 

c 



THE DlG£Sn'\~£ TRACT. 



LECTUKE VU. 



onuASs OF NrTEmoK. 



I>ieUiont of tJi9 JCtilritire li^fetaa. — 
JJirisiimt of lite IHgtttive Afptnth 
til*. — JfiMiuetire Vlturaftm t^'Jfu- 
tvtu itiul Serouji Mtjn6mH€*. — 7%e 
i'ompiHtition anit Ctirtti/iccrtion of 
the TrrtK.—Ihtcri}ii\<n of tht Jitic- 
cat i'tirHj/. — T/if Fharyrtx. — The 
(Ein>phwr,u.—T/ir Stf.n.'ach. — The 
/o*ir Sfnm* J/wiArow^.— 77-« J/m- 
com Coat o/lAe Somaf/i. — TXf fbt- 
iKie* of the. Stom<Kh.~71ie Ji)d» of 
the &vmacA. 

XfTRiTios h dinJed into tliree 
distinct imHressfji, vIt.. digestion, 
al)si>ii>tion.aiui tin-ularion. We 
shall (-•ommenct viith tlie study 
111' digf^tiou, aiid tlie dfscri|ttion 
of the imatomy of tbe aiijtaratus 
l>y wliirli it is accf>m]ili.»liet]. 

i, llie toiigue; '2, pharynx; 3, 
a'sojihagnji; 4, soft palate ; 5, sec- 
tion ^tf larjTis ; l>, hard jtalnte ; 
".epiglottis; 8,thyroid cartilage; 
9, ii'pimd «>nl ; in, liodics i>f ver- 
tebra" ; 11,12, spinous pr'->oeN*t« ; 
l.t, canliuf cud i)f the stomach; 
14, splenic extremity ; 1 r>. pyloric 
end; H>, greater cun'aturc; 17, 
lesser curvature; 18, the ])yloric 
valve; li<. first portion of dutwle- 
nuni ; 20, ttecoinl portion; 21, 
third portion; 22. mdl liladder; 
23,c\-sticduct: 24. Iiepaticdnct; 
2>'>, ductus communis cholcdo- 
chns; 2tl, its entrance into duo- 
denum ; 27, pancivatic duct ; 28, 
20,jejunum: .HO.ilcuui; -ll.open- 



What nro dto Jivbloni of Uie nntriiire ]inxm F 



I 



MCCOUS AND REEOCa ftlEHBRANES. 3» 

ing of ileum into large intestine; 32, ileocolic valve; 33, ileo- 
csBcal valve; 34, oecuin; 35, appendix vermifoi-mie ; 36, as- 
cending colon ; 37, transverse colon; 38, deeceniling colon; 311, 
Bigraoid flexure ; 40, rectum; 41, anus. 

For convenience of description, the dis^stlve apparatus may 
be considered under bix divisions: Ist^fJie moutu or buccal 
cavity; 2d. Pharynx; 3d. (EsophaguB or gullet ; 4tli. Stoiuaoli ; 
5tli. Intestines ; Htb. Glands, 

The buccal caWty is clostid in front 
by tlie lijjs, ■\vbich are composed of 
muscle (orliicularia oris), and cover- 
ed by mucous membrane. This mem- 
brane has a composition similar to 
that of the skin ; it secretes a glairy 
fluid called mucus, and lines the di- 
gc^stive apparatus throughout its 
whole lengtii, and may be described 
as being continuous with the skin. 
In some of the lower orders, as the 
polyps and hydra, it is not only con- 
tinuous with the skin, but it also 
can at any time, by merely iu\-ertiug 
the creature, he niatle to take on the 
action of the skin, while the skin be- 
comes at the same time the digestive 
smface. 

Mucous nieiubrane is generally in 
the form of a tube, and communicates 
freely with the external air. "W'heu 
it IS inflameil, the diseased condition 
tenninates in the ]iv(idiicti<in of J)um 
or matter. Semus memlirane, on the 

contrary, is always in the form of a closed sac, and does not 
communicate witli the extenial air. When inflamed, the dis- 
ease usually i-esults in the formation of adhesions which unite 
[the sni-faces of the sac together. Pus is veiy I'arely formed, 
when it is, it is a very nnfavoi-able sj-mptora, usually re- 
ing in iho death of the patient. 

Immetliately within the lips are the gums, composed of the 
Iveolar processes of the maxillaiy bones, covered by thick nm- 

a nppnrntiis? DcBprilw the liuEcnl rnviiv. Wlim 

' Whiit i) ilic Jiffarpncp in fiirni beiwce'ii mucnu* 

a iliQ rcailllB of innammatiuu in bolli mcnibriiaea? I)c- 




ANATOMY OF , 



eons membrane. In the gums the teeth are fitted, their func- 
tit»ii })eiiig to masticate the food, t-^ ^ 

Tlie jiarta oomposing a tootli aie the crawn, 
n, whiiTi pi-ojects above the gums, r,' the nnits 
Of fangs, /', wliioli ai-e fitted in the maxillary 
boncM. The crown is covered by a dense, hard 
material, called enamel,?; while the bulk of 
the t(X)th consists of substantia ostoidea, or 
bone ivory, f. The cavity in the interior of the 
tooth is n'presented sxtil. i>.ru«mi»tin«TMh. 

Tile substantia ostoidea closely resemliles l>one in its consti- 
tution, as is shown in the following table. The hai'dness of 



1 RniiTiicl. 




Done. 


Orginic utiliswnces a.r/J 

iHorgunIc ■' 1 m.n 


70.58 


38.SO 
6e.70 



the enamel is also itenionstrated to be due to the lai^e amount 
of inoiganic matter it contains. The cavity in the body of the 
ti-x^th is fillt^d witli a tiitty pulp, in which tlie bliKul -vessels and 
nerves sulidividc before they enter the substantia ostoidea. 
Fivm the great hiinbiess ami density of the enamel of the 
teeth, we snouhl hardly expect to find that tissue supplied 
with «• delicate a constituent as a nen^e, but the ])resenc« of 
nerves in the enamel is demonstrated t)y the pain produced 
when a sraall hard substance, as a grain of sand, is entrapped 
between the teeth while masticating. The nerves gain access 
t() tlie pulp thi'ough a canjd in each fiuig; whenever, therefore, 
there is nny iutlniiinintion either of thr fang or of the crown, 
the substaiitiii i)sti>idea is swollen, an<l,|nvssing upon the nerve, 
jiitHhu'cs tiMitliiiche, that most annoying of maladies. It must 
not be supposed, from the above statement, that toothache is 
always due to inflammation of the to<»th. as it is more frequent- 
ly a slight intlanuuation of the nen-e itself, a true neuralgia of 
the nerves supplying the tnotlu Tin)thaclie is sometimes very 
singidar in its vagaries; for example, the disease mav exist in 
a tooth in the up|)er jaw, and the patient will i-eter t fie pain to 
one in the lower jaw. and not be satisfiwl that he is mistaken 
until the wrong tooth is extntcted, without obtaiidng relief 
fit>m pmn. 

The nnneral substances of which the teeth are composed are 
^phosphate and tuHcnte of lime and fluoride of calcium. Th^ 



Whnt im tlif> larts miDTiMini; a luolh* 
nutlerlal in \he nmnH-l inil tali. oMi'lilrit? 
nrtui nrr ibc camci of luuiliiicho t Vi'hnt m 



V1i«i is ihi! rmpontoii iif nnimal aiul Oaaeni 
iVhnI is tliP pi>l[< ufihi? tmili n>Tn(aBnl aTt 
'1h« miMrnlMititUnccsMiaiKiMngilwiceibr 



CLASSIFICATION OF TEETH. 



3" 



I 



jii'e constituents of the exterior covering of wheat and other 
cereals; eonsetjuently, iu the finest varieties of flour, when the 
covering has hcen carefully sepurated, there is not a sutheient 
i|nitiititv of mineral substances to nourish the teetli properly, 
and we find tile results in the defective teeth of the children 
of tile wealthy, while those of the p<X)rer class, who live on a 
coarser fl<nir, have souml and perfect teeth, 

A viT}- coiiinion cause of hatl teeth is the use of preparation** 
of mcnuiT in cliildhood. Snch jireparationH seem to stimulate 
the growth of tlie teeth, and cause their projection abovo the 
gum.-' bt'forc they have been properly covered with enamel, 
which is the natural protection of the substantia ostoidea 
figainst the action of the juices of the mouth. 

There are two sets of teeth ; the fii-st is called the temitorary 
or milk set, nnnibering twenty, which are lo<isely fixed in the 
jaw, and are shed at tlie sixth or seventh year; their roots be- 
ing absorbed, and the teeth then pressed out of their sockets 
by the second or permanent set, Mhich begin to appear when 
the jaw-bones commence to as.HUine their final form. 

The permanent teeth are thiity-two in number, each half jaw 
containing two incisors or front teeth, one canine, two bicus- 
pids, and three molai-s. The incisors have a single fang ; they 
ng. «. Fie. «■ 




.bite ofl" the nioi"sel of food. The vaMincf also have a single 
ifeng, and are developed to a wonderful degree in animals that 
[^ive entii'ely on flesh, and are r^arded as an indication of the 
liabits of the cTeature to which they belong — all animals that 
■ have canine teeth being carnivorous, or flesh feeders, while 
Rthose that do not possess tlieni ore herbivorous, or vegetable 
(.feeders. 

The bicus])ida ha^'e two roots and a flat crown ; they cnish 

Fmm wlini nource* ni ~~~' 






-- . Dociilw sume iifllie rauoG* ihat produc 

toclh. Whaiisilie numlwr of milk IomU? W!iy ore ihevno cnltod? How mnnv wr- 
mnent leclli nro thL-re? Whon do ihrv nnKMirr Into wlint rlnssei sm iIikc diviiJed ? 
ni«nr of encli c1mi» in oneh hnlfjawP What do the cnninc tcerh miirkT flow moiij 
bnve tlie inciMn—canittra — bicuijiids? 



ADAPTATIOS OK THE TEETH TO THE FOOK. 



the morsels that have Ijeen separated by the incisors. The 
molars have three rotrts and a lai^e flat ctowti ; they conuui- 
nute the food as perfectly as possible, and put it in the iinwt 
fevorable condition for the action of the vaiious dicrentive 
juices; they ai'e developed to the greatest extent in herbiv«v 
pous animals, enabling them to crush and subdivide the grain, 
twigs, or grains on wnich they teed. Animals that h«ve the 
molars well developed do not jH>ssess canine teeth ; and in 
those in which the canines ai-e well developed, the m((lai*t« are 
changed in character — liccome cutting instead of crashing in 
Figso. their action, and are called camiv- 

l"^ , orous teeth. From the examina- 

tion of the teeth of man >ve find 
that the diet to M-hich they are 
adapted is that which the exjieri- 
ence of centuries has taught us is 
the best, viz., a projier mbtture of 
animal and vegetable substances, 
liis herbivorous wants Iwing shown 
by his molar, and hia uuniivorous 
appetite by his canine teeth. 
In some animals the teeth gi-ow with gi-eat ra])idit)-, and are 
only kept of a projier size by being 
"" '^' continually worn away by friction 

against the opposing teeth, as is 
demonstrated in I'^ff. 51, in which 
one incisor tooth of the upjier jaw 
having been broken, that of the low- 
er ja^v which oj)|K>sed it has gro\vn 
to sutth an extent as to form a per- 
fect circle, and finally caused death 
liy interterin<j: \vlth the power of 
m.'Uitication, tlie jaws being locked, 
together, 

The oraer in ■ivhieh the teeth ap- 
pear is as follows ; incisors in the 
seventh and eighth year, canines in 
the eleventh^ liicuspids in the ninth 
and tenth.and mohu^ in the seventh, 
thirteenth, twentieth to thirtieth. 
The Bides of the mouth are formeil by the cheeks ; they are 



Iimu Ijiwar Jtw. 




THE STOMACH DESCRIBED. 



39 



I 



composed of tlie buccinator muscles, wliich are covered on tte 
estenor by skiii, and lined ou the interior by mucous mem- 
brane. 

The I'oof of the mouth is called tHe palate ; the anterior por- 
tion consists of bone (palatal process of sujienor maxillftiy), 
covered by mucous membmne; the posterior portion is com- 
posed of muscles, covered by mucous membrane. The iii-st is 
often called the hard, and the latter the soft palate. 

On the floor of the buccal cavity lies the tongue, being foim- 
ed of muscle covered bj' niucoua membrane; it is very treely 
supplied witli nerves, and is the oi^an of taste. 

On the sides of the back part of the cavity there are two 
small projecting teat-iike organs called the tonsils; their func- 
tion is not known; In-tween them a similar process extends 
"rom the soft palate called the u^^lla. 
The second division of the digestive tract is the pharynx ; it 
a pyramidal-3hai>ed sac composed of muscles, ana lined vdih 
taucous membrane; it receives the moss of masticated food 
[from the mouth, and forees it into the cesophagus. 

The gullet or cesophagus is a tube formed of muscular fibre, 
land lined with mucous membrane ; it extends from the phar- 
ynx to the stomach, passing down the neck and thoi-ax in 
[front of the vertebral column, and piercing the diajihragm in 
course. The tibres of its musculai' coat are an'anged in 
ich a manner that some pass around the tube, and othei's 
along its length. It 
forces the >iolu8 of 
masticated food, by a 
filiecies of vermicular 
movement, fi-om the 
pharynx intothe stom- 
ach. 

In the adjoining sec- 
tion of the stomach, (/ 
represents the ojsojjIi- 
^us ; h, the greater 
e.\tremity ; c, the 
tKi.oBoiih„=t.«u.cii. smaller curvature; d, 

phe greater curvature; f, the pyloric end ;/,/;, the duodenum; 
of the liver and pancreas. 

] Describe the ti>siien composing llic c^hecks. What tissuo! Tonn the pnlaic ? Describe the 
kwRBtls in Ihc poBtuiior pnrc of 'he liiicml CBTity. Descrilie the pharynx. What li>snc» 
totiipiHie it? Describe llie cesopluicai. Wliat liuties tampOBe it? Whnl is the couric uf 
"fi ueiMiphnEns ? Kow does it nci? Deicribc the position of thosloniach. 







THE THREE COATS OF THE STOUAal. 



The stomach may be dwcribed as a pear-sbaped organ, lyi 
in the up|)er part of the abtlomioal cavity, partly nuder the liv- 
er, ami in the median line of toe LhmIv. with the larct; end on 
the h'ti side, aud the lesser or pyloric end on the right ; when 
it is empty it collapses. and occupies a very small space; but 
^vhen it is distcudw either by fooil or gas, it can be made to 
hold slnnit one gallon. The walls of the stomach are ccmiposed 
of three distinct membranes or layers, an interior coat of tuocous 
membrane^ a middle or miiscular.and an external or pemus layer. 
The serous coat of the stomach U a portion of the petitune- 
um, or great sen.nis membrane of the abdomen, whicli covere 
the interior walls of that cavity aixl all the or^ns it coiitaiiis, 
cuablius; them t»» move readily over each other without friction 
durin? respiration and digestion. The other semns membranes 
rie w. "'"^ found «ivtrring the brain, Inngs, and heart 

Tlie synovial sacs of the joints may also be re- 
spinleil as Wli'nging to lliis class of mem- 
Itranes. 

Tlie muscular coat i** composed of inrohni- 
tary fibre, formetl into bands i)r biiudles, Eome 
of which mn arouml the greater diameter ot 
the organ Cf')/- o-'*. l\anu others anmnd the 
lesser. '2. Their duty is to cause the stomadi 
to contract on its contents e«imdly, or to im- 
part to them a movymciil "f rotation, by 
which they are mixetl ivithAvrtain juices, and 
diffi'stiou iissisttxl. At JiJTAiXit' 

TTie mucous ctmt lias wsi>ecjal limction to 

perform, viz.. the stHirelion of the gastric juice ; 

It thcrefoiv differs fn>m the other membranes 

of the same class in lieing provide*! with a 

number of glove-shajx-d depressions or 

follicles. The interior of the follicles is 

iiinil vnth secreting cells, which Ibnu the 

gastric juice most actively when fiiod ie 

intHHluceil into the stomach. 

The o'sophagiis enters the stomach at 
its large end ; and, since the entrance n 
on the left side, and under the heart, it is 

VThai B ici iIibh — liie? What tUBOr* rampmc iii valb? IMmi U the [icriM>iNn»r 
W1i«r« iu« ihe oihrr icruo* ntPinhmm foDiiil ? What tints of miurir crib ii<«nt««e 0m 
mOMtiUr roll of the iiomiich f Wtwl it tin* ifitTT ot llw mafrnbr larpr t What i« llw 
ranaioii of The muroiu roaiF Wtiai aro ihr Mlirlc* of ihe 'Imnach? What i* tbcjrflrae- 
lionT Namo tbc cndt of ihc Womach. &i wliich end dunihe a p j p h afyacMerf 




DIVISIONS OF 'niE INTESTINES, 



illed tlie cardiac opening.- After digefrtion 
ly the gastric juioe is fonijileted, th« fluid 



formed escapes int< 
opening at the ojii: 
ipeuiiig, which 



the 



through 



tiue 1 
id, failed the pyloric 
meuiiig, whicti is dOLsed tiy the j>ylorif valve, 
lo this valve gi-eat importance was attached 
by the ancients, who even believed it to be 
the seat of the eonl. 

The coats of the stomach, and especially tlie 
mucous coat, are very freely 8ui)plietl with 
blood-vessels, which are intensely congested 
during (ligestion. The supply of nen'ous 
tbi-ie is also veiy large; one nei've in particu- 
hir, the pueumogastric . which is derived di- 
rectly from the brain, and jiasses thi-ough the 
thoracic cavity, erivine brandies to the tunsts s«uini>afi>imn»)iFoii[iaM. 
on its way, seems to have control ot the move- 
ments of the organ, and also to influence the secretion of the 
digestive juice; for when it is cut or injured, the niovt-ments 
of the stomach cease, the gastric juice ia secreted at a slower 
nte, and digestion is performed veiy imperfectly or uot at alL 




LECTURE Vni. 

THE INTESTINES. 

8 of the snniU Intasline. — Cnata of the luteattnt. — Movements of 
the Iiitesline. — Valoulfe Conmeeiitea. — ViUi, their Cumposilion. — Uivi- 
aions of Ike large Intestine. — A/ipendlx Venniformia. 

From the stomach the food passes into the small intestines, 
nrbich are described as consisting of three divisions, \tz,, duode- 
ittuiu, jejunum, and ileum. 

All the divisions of the small as well as of the large intestine 
_ ; composed of three coats, like those of the stomach, viz., se- 
Tous or peritoneal, muscular, and mucous. The extenial ami 
middle are the same throughout the intestinal canal, the mid- 
dle or nuiscular consisting of two sets of iuvoluntaiy fibres, one 
of which passes around the tube, while the other nms along its 
length. When the muscular bauds contract, a ver ij ^ ncuhir or 
vviimi-li];p i ij iitjoi] is produced, which propels the contents of 

Ive? NimHTth^ Wvc i-f ll.c Moinwli. mere docs itTnkp il« m- 
i->n7 Whni are tliu ilivmuns of the smnll inlcilinc? Nnmc tlu 
N\-.\i U ilic funciiun of ihe muscular com ? 



43 TlIE SMALL ISTESmXE. 

the tnlw (loimwanL In perf*^ .iH-alth, thv motions of tlie 
stomarb go on without our knowKnlgv ; tuit when the fitoii is 
Dot properlv d^**ted, ibe ixmmctMtn?^ become mure rioUiit, 
and wvcn- colic is jmi«lu*'eJ. Sotaetimis the movement^ of 
the ni(i.-<-ular ItauiU art inv^-rtird. anJ ihe (Xitileut* of the t^oiu- 
acfa autl iutwrtincs foixwl upwanl, ns iu vomiting. 

The intt-rnal mnciMis f>«t diffpre in the «iifftrt-nt parts of the 
caual,flnii mav wiih advantage be cousidtred witli the dLiK-np- 
tioD »f t-ach divisioo. 

^ Si TTic duwlenum is ulev- 

^^^^^ ^ en int-hes, or twelve fio- 

^^^^^^# ^r-hreadths in length ; it 

^^^^^^^k shspetl like a horw- 

^^^^ ^^^U^^^^ shoe, »o that its end Im 

^^^^H^^L ^*^^^^^^^^ undtT and a little bi-bitid 

^^^^^^^^^^L ^^HH^H The 

^^^^^^^^^^^^^^^^^^H character, the upjier iMUt 
^^^^^^^^^^^^^F for All or no mun 

^^^^^^^^^ the pyloru-t being smooth 

^JT^^^^ or tlimwn into vertitaJ 

""" folds. A\Tien these existt, 

they diMippear in the second inch, transverse folds taking their 
place, which are called valvulit conniventes, and their funetion 
f^iems to Iw to pix>\-ide the neces*ari" antount of memVtrane to 
enalile the canal to he distended ; it is also supposed that thev 
may 1* of use in retardin<r the patwage of the food down the 
intestiop, and, by eiving to it a movement of rotation, assist in 
completing digestion. 

On the val\nlje conniventes there are niimitc projections* 
whieh may be seen by allowing a stream of ^viiter to run for a 
short time on a portion of the intestinal mucous membrano, to 
wash tlie mucus off, and then placing it in a saucer under wa- 
ter, when the villi are visible, giving to the membrane an a|v 
pearance similar to that of cut velvet. Tliese minute projec- 
tions are found in the lower jiart of the duodenum and throueh- 
out the intestinal canal, but chiefly iu the middle region of the 
small intestine, 

■ The second division is called the jejunum, because it is gen- 
erally empty when examined. It is al»out tercet in length; 

Dinrriln ihe ilinnlemim. Whnt is iho conrM nf llic folila in tho fim rmrl of ihc dirade^ 
niitti ? n«cribn ihp t»tni1« n.nnivcnlci. Whnt ii th-'ir fnnciinn } W list kLtt* ih« no- 
riHiJi mcmlirnnc ii> trlntj appearance? Where are the ftUi cbwflj-faiimlr Dracribe ih« 
Jrjuiiiiiii. Wbal b iu kncib ? 



Tin: SMALL IHTEsniTE. 



^X^A A f , ft 







i it the Talvoltc conniveiites are verj- pTOinincnt, and the villi 

meroiis. 

The thii'd division, or ileum, i-eceivea its name on account of 

B intricate twists into wliich it is thrown; „,, „ 

■alH") is fi-eely supplied with valvulie aud 
uli,but they become less and le'ts marked 
bwanl its lowt-r extrt'mit\ The length 
of the ileum is about fifteeii^jet 

In the figure the vir[imt^>ii--'Lnttd \t 
a ; the glands of Lieberkulin, h niu>i iil n 
eoflt, f,' follicles of Peyer, </, hulinunou-. 
tissue.'.' cinndar musculai band's/, 1"" 
t^itiiiiinal bauds, j/, A. 

Tile total length. of the tmall intestine 
is about twentA^six tret , and iti diann tt i 
line inch. By some the (luodmuni i^ i 
garded as a species of vftojid stuiuuli 
but, fn>iu the above statements, we fin'! 
that there is no proper foundation for tin 
opinion. 

From the ileum the undigested ftfod | 
passes into the large intestine, the length 
of which is about jjj^^k^ ; ad<ling this to 
the length of tlie wniall interitine, stomach, and resophagus, ^ 
lind tliat tlie (otal length of the digestive canal in a pei-son suj 
feet in height is thii-ty-foui' fe et, or nearly sixtimes the 1 ' 
of the body. The diameter of the large intestmeis alxjutT 
incties , and it is divided into six division,'-, vjy.., ea?eua 
mg, transverse, descending eolon , sigmoid flexui'e , and rectum * 

'Hie cp ^uiQ is the commencement of the lai-ge intestine ; it is 
on the nght side of the abdominal cavity, and is separated 
from the ileum liy a valve called the ileo-cu'C} )^ •^'alve. which re- 
tards the 'passage of the portions of loouthathave not been 
properly (ligested in the small intestine. The cit'cum is de- 
scribed !is beiug pouoli-like in fonn; it is attached by its exte- 
rior jjortiou to the wall of the al)domiual cavity, in the right 
iliac region, so that when the lowei" jmi-ts of the large intestine 
are closed by disease, and the fasces can not pass, a fistula or 
"^ rtlficial communication may be made with the intestine in 

\_ JlcM'rilM ihe iltftim. IIo>r long v. il? Whnt li ihc Icnglh uflhe \tx^ inleslinr? Whnt 
^lUiliBifitflur? Whni is tho toinl length of iho Jigpsiive nppnmius? WhiH nrc tlic Jivi»- 
portlie large ininilne? DctcrilM tho cncum. Whnl Uiu po«irion? Wlini valve wp* 
il from ll'.osiiiaU inlMtine? 



Acd WOlMnoMn. 



44 THE LABG£ CTHSTCTE. 

th> T^'^.rz.. ir.1 the lir- ••: the y«atient prolonged. This is 
-H r.i-:::::.— 'I-Lr. iL:'U:jli -xi<r!::'.>- nicst ^e almost unendurable 
"^rL-:- 'Vr -.i.r.*:l.-r :Lr 'IIm-i n.TV'rt'i ii:d &nnovance$ which at- 
:-r. i ZL- r.-^.>— ::y • ■: c^n :\rtir^ iil anxi^. as it is called. 

T- » :L- ciLTrrr!' •? -^urrV-i.-e ••! thr i-trvumua small irorm-like tube, 
rL- :i: : -: ::x vrrTLirrriLi^. is artactr^l : it is not of any use in 
r:.:i:-. :.. ■ :j':. :: '> •irrvrl.'f ►r^l r*» an t-n«.>rmoas extent in some an- 
::Li^- :i:. i ' ir^is, '^ ^o. ilil;^' • r.- •:•: rhr inip-^rtant divisions of the 
ii:;j>— ::* - vili.aI. :Ui'i*!vach:i:^ in :he i^rich a length of neariv 

T::- '.jl: :1. • :'i: i^rr.'iLx i-^ r/.eivlv rufiimentarv in man.andhas 
:■• -•-viiil '*. ::y. :: i^- 'r y n • rnr;ti:> ro Ve overiooked or disre- 
«-:\: 1" i. : r it • r:rn L:ij : t'^s tLit an undigested hard snl^stance, 
lik- ;L .*.-r7}--:' :.-. :> ■ y s ri.r :ivx-i«lrm caught in the mouth 
• : :':. - :^- :-:. lix. a:: 1 • 'ri^i:.:!:--- ;ii: iutiammation similar to that 



jr -r: -*i 'y ;; -^l::::^-r ::: :':- ^k:n: this mar continue for 
L. :.:1.-, :.L. i I k:. v . :* . :. - ::>:a:K'e in which a cherry-stone 
%v;i- :;..; ;i. tr '• ::. :!:-. a: :x:.l:x, :.:.'l rrmaincd there for manv 
vrar^. I :• •i:;'j:::_- -; :Vt ::. o ::vi:I-:. ns-uid finallv cau?ed deatL 




O -^i •.. . 



I • 



:: T ::--*.< ii;- • :: th xvS^r. >:<lr* aud terminates in the 
:*- ■ </» * •:.. • r ::::r*l Ji\ i^i- :.. v. hivh on>S5es irom the right 
^:: -: 1 .Ivii.j: ::::!ut^l:a:^>. :::.»Kr the stomach: reach- 
iLj :..'• \ T. >: Iv. :hv o '» :; ».i:rvr< .'. ^vnwArvl to form the fourth 
'iivi-i : . ■ r •'.■ -Mcrrjil: .: v» ^•:., wh:/::. ::i rhe It-ft iliac tbssa, be 
o ::: - :l:. S -!::i; vl ^urv • vzi'.'*-; :!:f siiin-oid flexure, or fifth 
♦iivi-i. :.. Tliv r*.:! . t rV.is ::rxur\, . r Vriid of the laige intes- 
ti:> . '.: - ::. rlii- Vij'W r {art « i' :lu ; - 'vio ^.tivitv, opposite the ra- 
{"rii. : -iiTcuv . f i\w >iur-::r. : tV^ !u :hi> |>innt the intestine 

Tur.virv v^f the sacrum, and 



{:>-«- L w:i^vaM, :..,.. »\v:!:j: ::u vATur.viry v^t the sacrum, and 
t- •?:::::._■ :!>• <ix:'.i »iiv:-:,r. . v uv:v.:i:.Avhioh is olosetl below by 
a K.:. I . r* v. ■:::.::,:% ! .v.<<\:-ar h-rt- x::ar forms the anus or 



~ • • L . . .^ , 



T;. • i.'^:;:< • t :Iu- larc*.- ;v.:^'-*:tv.i- arv- thr -<Hrae as those of the 
jr; 1! :::i. • i:t Uss nwly ^i:p|u:oi with vilH. Certain srlands 
a:v :•*> . i'ui;l i:i rliis \K\n ot ilio ilicisrivo mucous menil^rane, 

r- ". - • • *: '. vr/.>::»v^v^ :* :.-o .»:tx'r%v.\ v-:?"^,"' :x: \V>,r.' » :'. « asrciKling coIoh? 
\V" »-x.' * ■ •r*:>^ *•!>*• o '..•:• \V o-v* > : o Ov^.vvv.^j: <\<xc? \\"b<re anil «hat is the 



^^Buccal Glands. — Description of the Salii-as. — J'rofiertiea of mixed Saliva. 

^^f — Mtlure of J-irmentx. — Atidomiual (Jlanify. — ihiti/ of the Liver. — Na- 
turr and Pi'0}Krlies ofJiiU. — 2'/u: I'ancreaa. — A'rtturt and Propertiea of 
iVj Hecretion. — On;/in and Prapti-tiea of Gastric Jaice.~U»es of Pep- 
sin, — Origin and Projierlies of Intaitiiial Juicea. 

AfrTt:!: the fond lias been properly 8^btli^■i^^ed, it ia mixed 
witli ffitaiii juices wliich are secreted by glands. Tlie glands 
are lUTHiiged under tlie follow-ing Leads : 1st. Those of the biio- 
t-al ea\itv; 3d. Those of the alidominal cavity. 

The glands of the buccal cavity are ° 

the parotid, submaxillary, and «ublin- 
giial; they are also called the salivary 
iilauds. The parotid gland, -p, is Ite- 
neath the ear, and behind the lower jaw 
on each side; its setietion is conveyed 
to the mouth by means i)f Steno's duct, 
K, which crosses the buccinator muscle, 
:nid |)ierccs it near the centre, deliver- 
ing the sjiliva into the mouth opposite 
tlir second molar tooth, so that it is min- 
;_'l('d with the food while it is being 
tii:i>*tii-!ited by the teeth; it is well 

itdapted to the purpose of forming a pasty mass wnth the food, 
for It contains more water than any other saliva. 

^The submaxillary glands are behind the horizontal jiart of 
e inferior maxillary bone ; their secretion is more eousistent 
tnan that of the i>jin>tid gland, and is conveyed to the mouth 
by Wharton's duit, which opens close to the bridle of the 
tongue. Tile sublingual glands are under the tongue on each 
side of the bridle; their secretion ia delivered by fifteen or 
ffenty duets, which perforate the umcous membrane of the 



llIE BUCCAL GLANDS. 



LECIPRE IX. 





iHSBPs nrc thcEliinilxUh-iJpcIF 
! iwsilion of lliP imrotia kIhh,!, Wh 
the runriion of )i'"^'><i *"!' 
iluci? Wlicro docs it c 



the glnnds of tlie Lnrcsl ciiriiy. 
n nat IB itio nunc of its duel ? WlinC in ils'm 
Wlicro is [ho iiubnin:cillary Rliind ? Whnt i 
ihc montli ? Ucscrihu tho sublingual ginnds. 



I 40 PICOPEItTIES OF SALIVA. ^^^^^^H 

I floor of the mouth. The function of fmbiaaxillai^' and sulilifr 
gual (tfiliva is to coat the food with a slUuy material, \t'liich ft- 
I cilitates its pa-ssage into the stomach. 

Tiie aecretion of the glands of the buecnl cavity, togetlwr 
mth that of the mucous membrane, is caJled mixed snliva; il 
is alkaline in itn reaction, tuniinL' red litnme blue. Tlie con- 
Rtitui-nt wliich |)roduce9 this result is free lime, as 13 .shown by 
the jH-lliele uf carbcuiate of Ihne which forms on the fsui-face of 
saliva that is allowed to stand in the open air. The total 
amount of saliva secreted in twenty-four houre is fifteen er 
twenty ounces, but it depends to a great extent on the excite- 
ment to which the glands are subjected. During the ma.'^tiai- 
tion of food, or in speaking, the secretion is greatly increased; 
mental iinpressions produce a similar i-e*ult, as the exjH'ctatlon 
of a good meal, or the odors given off during the co(»king of 
vaiious savory dishes. 

/ One of the most im]iortant ingredients of saliva is a nitro 
Igenized body called ptyaline ; it belongs to the class of ler- 
' meiits Avhicli possess the jxiwer of causing other substances ta 
undergo chiuige with more or less rapidity. Each of the di- 
I gestive juices contains n teiiiient, and tliey seem to he essential 
, to the proper perfonimnce of digestion. Tliey are all Viodies 
i which may be said to be in the act of undergoing final decora- 
; position ; and it is one of the most beautiful Illust rations jn the 
1 whole domain of physiology of the manner in which niateriaU 
; are consumed, that the dying, effete nitrogenizeJ substances 
) which aVG no lunger of any use in tlie system should, in being 
{ cast out, aid in tlie introduction of new luitritive material^ 
I teat^hing us the lesson that in the laboratory of nature nothing 
^ is lost, nothing is wasted. 

■^ The slimy nature of the submaxillary and sublingual juices 
also causes a considerable amount of air to be eub'ai>i«f<i with 

»tbe food and cairied into the stomach, where it assists the dl- 
MBtive juices in dissolving the JImxI. 
■ijlie abiloniinal glands connetted with digestion ai'e the liv- 
er, pancreas, stomach follicles, and intestinal glands. 

The liver is the largest fiifljld in the body, its weight l)eing 
fonr pouuds; it lies immeoiately over the stomach, and is 
held m position by ligaments formed of folds of peritoneum. 

Whnt U Lho function of submnxillnrv nnd eublinKiinl wiliva? Whnt i* llir rcnnlion uf 
inlxcil mlivn? Wliai mibetnnoo c'"^ '" ihis-renction? lli-ie mnrh pnliTn i^ norrfird in 
twimty-fniir lioom T Whnl cmiscn influence iho jiroiliiction of «ali™ ? Wlini i* ihn fcnnffnt 
oranlivn? Whnt it iho cnmpoiltinii nnd nninrc of fermiMitaF Wtini apcriitl ritiictinn dcea 
■ubuiHKillnrr snlivniirifomi? Name ilie alidoniinHl glanJs. Wliai is ilia nciclit of ihc Ii«^ 
erf DcKiibo iti uuition. 



d 



TIIE FUNCTIONS OF BILE. 



4r 




6 is divided into two lai^e lobes, the rigtt being the larger ; 
i«ddition to these, anatomists mark out two or three siiiiiUer 
It is fi'eely supplied with blood by arteries, and also 
ieives through a short trunk, called the portal vein, the lilood 
I all the other organs in the abdomen except the kidneys. 
%e gall-bladder is attached to the under surface of the liver, 
^d serves as a. reservoir in which the ^,__^ 

I of bile is retained until it is re- 
1 tor use. 
Ju the adjoining figure the right and 
\ lobes are represented, togetlier with 
Be blood-vessels of the organ and the j 
gall-bladder. 

The liver separates bile from the 
biiiod, mid empties it, by means of the ThouvM. 

hepatie ducf, into the intestine. If we examine the blood be- 
f.in- it enters the oi^au and as it passes out, we find that sugar 
has liccn funned, and a certain quantity of fat has disappeared, 
^^liowitiL^ tli;it another veiy imjiortant duty of the liver Is the 
transf'.irni^itii.iii of fat into sugar, and that it is intimately con- 
nected with the function of respiration. It also produces a pe- 
culiar fat called cholesterine, which is employed as an external 
L'overinaj of nervous fibres. 

Bile is a yellow or green fluid, witli an alkaline re.iction, due 
to the presence of free soda. It is not fomied in the livi-r, but 
in the l)lood, the liver merely filtering it out fiom that fluid. 
The total amount secreted in the course of a day is fifty-four 
ounces. -^ It is the natifral stiinnlant of the in^estinef' . as is shown 
by the fact that when it is deficient in quantity the intestines 
act in a sluggish manner, and only resume their enei^y again 
when the secretion of bile is increased either naturally or by 
the use of medlcinea 

It has ijeen sujfposed by some physiologists that bile was an 
important agent in tlie digestion of the food, but this opinion 
is m a great degree controverted by the fact that the secretion 
of this juice is most rapid about thirteen hours after tlie chief 
meal ot the day, and at the time when the intestinal action is 
most enei^etic in tlie endea^'or to remove the undigested mate- 
rials to the lower part of the digestive canal. 

Prom ttbat noiirces duoB ii rercive tiloml ? When is lira pnll-lilnildor ? Wlint is \U fnnc- 
lion ? What U the itiitr at lliu trvrr? Wlint cliango io impvcscil nil Iho blood diiriii)! Jti 
TO through the livor ? Wlint is pholc-K-rino ? Whnt ii its ftiticlion ? Dpscribu liilo 
M proportlct. Whciii la it formed? Whaii» Iho diiimnlaniuunt oftiitc? Whntiaiu 
ion? At what time ti bile iccreied in larcesi qnniiiit^ ? 




PANCREATIC DIGESTION. 

Tlie pancreas is represented t 
o ill the adjoining figure, ff haioi 
tbegall-bludder; ^,the cystic dud 
c, the ductus communis clioledo 
chus ; ^,the pyloric valve ; e e,ih 
duodenum; i the termination ■ 
the iluodenmn 

Tlie pincreas reBem>)les tlie saI 
uai\ „Uih1s m its stracture; 
\ iiit-t III -.i7e tteishing fi'om j 
^11 h\n (in|uis. Itlies in tlte curvi 

ot the duodenum, across the ve 

tebial Lolmnn The duct com 
menteM it the small end and passing out at the head of th( 
gland, unites with the ductus communis betore it pierces thi 
mtestine. 

The common duct of the liver and pancreas is about the d^ 
anietei- uf a goose-tjuill ; it enters the duodenum near the 
tjt: of the middle TOrtlon, passing through the coats in an ot 
lifjui.' iiijiimer, fonning a valve. 

The diurnal secretfon of the pancreatic fluid is about ^uA 
ounces : it is alkaline in its reaction, owing to the jn-esenee o 
soda; its ferment is called pancreatine. The special fuuctioi 
of jiaiid'calii' fluid is to digc-^t fatty btidiesj as is demonatratoi 
by tlir tiu't tliat wlii-n the ]iaiicreiii- is discfif^td, these substance 
aiv not di,i;i>>.tcd,but pass <'ul in tlic fiecfs. 

Tlie stomach tblliclea have been described in the discussioi 
of the nmcous raenibraue of the stomacli. They secrete a fluM 
called the gastric j nice ; it has a strong acid reaction, owing t 
the presence of hydrochloric acid, which is foi-med by the dfl 
comjiusition of common salt in the presence of Avater, as is e* 
pressed by tlie following formula^, which also demonstrate tfaa 
soda is at the same time produced, and, as we have seen, make 
its appearance in the bile and pancreatic fluid. 

r-Ni.llO, Swia. 



^ The ferment of the gastric juice is called pepsin; it may \ 
collected in quantities from the stomach of the calf for the pu] 

Describe ilia pnncrroi ; ilsivcic^l: posiiinn. WKai is tlic rniilm nf i!n dnrl? Wluu 
the diiirnnl ntnoiiiii of pniiiTontic fliiiil? Whnt is it* speciiil fnnciinn? Wlmi i» ilio ic« 
lion of B'wtiie.iiiiec? To wlint Biibstnrico is ii» rceriitm liuc? Ex|ilniii tlio origin and fiwi 
mlion of tbe aciJ. Wlialia Ihc fcrmcnl ofgailric juico? 




INTESTINAL GLANDS. 



49 



noses of expeiiuient ; its functioa, as we shall fully deraonstrate 
hereafter, is to aid the acid in dissolvin" certain articles of 
foo,l. 

The intestinal jviice is secreted )iy a number of glands, class- 
ified as, 1st. Briinner's, which are about the size of hemp-seeds, 
and scattered th run shunt the intcstiuf:*, Imt nn^ chiefly fuiiud 
in the niui-nus iiif'iiilirani' uf till' np]nT piirt uf tin- siiuill intes- 
tine; 2d. Till' tuUidea (■fLiclierkuhn, which resemble tin' stom- 




FoUIdo or LkbarkubiL 



ach follicles; they are also found in all parts of the intestinal 
mucous membrane ; 3d. Peyer'a plates, which are circular glands 
without ducts, and fi>und m the lower part of the small intes- 
tine and the colon. 

The intestinal jtiice is acid in its reaction, and contains a fer- 
ment similar to jiepsin ; it acta upon the same articles of tbod 
as the gastric juice, dissolving those portions which have es- 
caped stomach digestion. 



LECTURE X. 



Annual Amount nf Food consumed. — The Jitgesta. — The Introduction 
and Pie of Water in tlte Smtem. — Latent Heat of Vapor of Wala: — 
Variation in the Food of different Nations. 

Havikg completed the study of the various parts of the di- 
gestive apparatus, we are prepared to examine into the duties 
of each poition ; for, as the characters of the juices in the dif- 

WhM is the function of pepsin ? WKat ia the Kurce of (he inteEtinal juice ? Pcscritw 
BrnnncT'i kImiiIii. Whal are Lieberkabo'i follicles? What are Pejer'» plateBf What arc 
the propettiea of intestinal juice ? 



Oy) NATURE AND PltOPEllTIES OK INGESTA. 

ferent divisions of the digestive canal diffei-, bo also do tlie 
differ in their action, some articles being digested by one jui( 
and not by othera 

That man is a destructive machine is abundantly proved b" 
the tact that in the coui'se of a year he takes into his systen 
more than three tlionsaml poinids of materials; and, since th< 
weight of an adult docs nut increase, a similar amount mU9l 
also ))e voided. Tin; iiiaterinis iuti-oduced are called the itt 
gesta, those voided are called egesta. 

the iugesta may be classifieT^muer the following division^ 
tin- amount of each class having been obtained from the anni 
and na\\ ration scaler of different nation**, and bj experimoi^ 

Ainual Injala 



The egcBta also amount to 3100 pounds, and tonsifet of expired 
air, p(tt.pnation,iiime, and faces 

Watei niaj be intn>diued into the syitem b> immersing the 
body in a warm batli, after which it will be found to have !» 
creased in Avcii^'ht, the amount of increase depending upon tl 
previ<iua alistinciu'e from the use of liquid. It is stated thai 
shipwrecked sniloi's, whose bodies are exposed to c'ontinue< 
contact wilii wati^'r, do not suft'er tliirst, the liquid being iutro 
duced through tlie vessels of the skin. 

/ The uses of water iu the system are, Ist. To form the food 
into a solution, so that it can lie taken uj) by the vessels which 
are intended to absorb the. fluids produced by digestion; dd. 
To form the basis of all the circulating juices of the l)ody ; 3ti< 
To keep down the temiwrature of the body to 98" ; and, -11 " 
To carry effete or oxidized substances out of the system in : 
lution. 

■ In order to appreciate how powerful an agent water is .,^ 
conti-oUing the temperature of the body, we have only to exam 
ine into the change it undergoes in being converted mto vapoi 
or steam. If we take a given (juantity of water and subject it 
to the action of heat in such a manner that the temperatui-e of 
the mass shall rise one degree per minute, we find that it wil] 
follow the law until it reaches 2 12°, when the temperatiire 

Wlmt in tlio anniinl iiinnunt nf inceetn ? Wtint arc tliu pgeMn ? What arc ihs dirUoH 
of llic ince»in ? WhiU i'. ilifi nmm.nl of pad, ? What nrc the divi»ion« of tlie i^nMl 
How miiy wnwr be inirojiici'il into tho tystetn? Whai ar« the fimeiiom oTitMer iK |' 
qrncn] T Uow doci naicr conirul ibc lempcrature oi itie body i 



FUNCTION OF WATER IN TOE SV3TEM. 



51 



longer rises, but remains at tliat point until the. liquid has all 
evrtixjratetl as steam, which requires 1000 minutes. If we place 
a tliernioiuetev in the steam as it Hses fi'om the water, we find 
tlmt its teinpetiitm-e is the same as that of the liquid, although 
it lijis ahsfirhi'd all the heat that was passing into it for IdOO 
iiiiiiutes. Fruni this and other experinieiitM, we find that steam 
dillVrs from water in containing 1000 degrees of Iieat in a la- 
tent or hidden form that is not appi-eciatetl liy the tliermome- 
ter; ci»iisei[ueiit]y,the total amount of heat in boiling water be- 
ing -ll-l". tliat citntflined in the steam rising from it is 1212°. 

Ap])lying tlie aliove facts to the explanation of the results 
jii'iduLi'd Ity tlie evaporation of water from the skin and lunga, 
wf Hijil tliat the vapor of water, which is amtinually rising 
fium tin- HUifaoe, conveys away the excess of heat that has been 
generated during tlie neifonuance of the vaiious functions of 
tlie different parts of tiie iKKly. 

Water, food, and air constitute the ingesta of all men in all 
parts of tlie world. Of tliese, water and air present but very 
slight modifications or vaiiations; they may therefore be regard- 
ed ius iiivaiiable in their character. But this is not the case 
with fiiod. The EsquiniaiLx or Laplander will devour an enor- 
mi lus amount of oil or whale Idubl ler, and would at any time 
prefer a lump of tallow to the mcist daintily-served entree, 
\vhile the West Indian can hanlly be induced to eat any fat 
substance, lint delights in fruits with which uatui'e generously 
supplies him in great variety. 




LECTURE XI. 



DIVISIONS OF FOOD. 



r, fto Composition and Variations, — The nitroffenixed Orovp. — 7!ie 
I non-nitroffctiized Group. — Hydro-cardotis. — Carbo-hydralea. — Permenta- 
Y tton of Starvh and Sti^ar. — /«j?mcticc of Temperature on J^ennentation, 
h^ComjJosition of Flour. — Breail-making. — Wine-making. — Use of 
mj^ioaphate of Lime.— Of Chloride of Sodium. 

__, TnoiT.n the diet of adults may be variable, such is not the 
case with the newly-bom infant, for milk presents a unifonn 
constitution as regards the nature of its ingredients, though 
their proportions may vary. 



52 TIIE NITROGENIZED GROUP. ^H 

CompiaitiBH of Cew'i Milk. 

W«ter 873 

Casein 4S, Kirn.Bcnised niid niiirifire. 

IK;;::;:::::::::;;:;:::::::::;:::;::::: m}«"i™..^ -" no,,..i,„„„i^. 
Sr!:™;:'."":^;::;::;z::::::::;;;_l|?l«- 

100U.00 

A glance at the table shows how many different kinds ( 
fdoil are contained in milk. Of these, wattr stands first in inl 
portance as regards quantity. The variations in the amoun 
of this ingredient are of minor importance so long as tb 
natural supply is considered ; but this is not the case whei 
from deficiency in the natural supply, or from any other caus< 
cow's milk is to be substituted, Iti this case, since nnimi 
milk is so much richer tlian human milk in such nutritive sub 
stances as casein and butter or fat, it must be diluted wit) 
three or four times its volume of water, and sufficient sugj 
added to make it sweet to tlie taste; it then forms an exvn 
lent substitute. But if it is not properly diluted, it often disi 
grees with the child, giving it diarrhcea, and finally causitij 
death. I have fi-equeiitly been surprised at the Mant of L 
formation that exists among mothers, and even amoue; pfaj'sai 
cians, I'egarding the above simple facts; and have aided in prfl 
ducing the i-ecoveiy of infants that Jiave been wa.stcd away 6 
mcif skeletons, by simply dii-ectiug attention to thtir diet, and 
causing the milk which had been given in the undilut^-d sfat 
to be projK'rly reduced with water, in order to adajit it to tli8 
digestive pow lts of the chihl. 

The second ((iiniionent in onler of quantity is ijagyi^ which j 
furnishes the curd wl^tju the flui<l turns soi i r . aiRH^he mat* I 
rial that forms cheese. It is composed of the chemical elfr I 
ments, carl n^n. hydro i ren. oxygeB. and nitrojj^ ,' it in th^l'efon | 



•Qiren . 
eusul 



L 



called a nitrogen ize< I substance, and is one member of an iiB-, I 
jKtrtant division of food, the ntliers being, 1st. Fibrin, wliick I 
possesses the ivmvr of self-cnagnhition ; it is formed in tltt J 
blood, and is enqiloyed in nourishing muscular tissue, of v 
it is tlie chief constituent; 2d. Albumen, also found in blw 
but existing in a purer state in the white of eg^s; it does ii<| 
coagulate spontaneously, but can be made to assxmie the s 
fomi either by heating to lHtl° F., or by adding certain « 
or other chemical agents; 3d. Gluten, or vegetalde fibrin,! 

Wlint aro the iii(n«dicTiIa of milk? DovR hnmnn milk vnrf in \t» cunigioiilion F 
Tiiricu of milk ^«^w^lUlelI lit.miin milk? l8co»Vinitk siilinbic fur mUmfi Whai b «l 
in? To nlini eroiip ottiioA dues ii belong? What are tbeoiher memlicrs of tlMofm 
izcd group? What are iliuir {iropcnJCB? 



DIGESTION OF NITROOENIZED SUBSTANCES. 03 

be obtained from any plant, or from the flour of various 
seed^. 

Professor Plaj"fair says, " Ve^etal)lt's arc the true makers of 
flesh ; animals only arrange the flesh wbieli they find ready 
formed in auimals and plants. If we go farther dowu in the 
chain, we find all food in the deJ>ri>i of rooks, for the bre-aking 
np of these form the earth, from whieh it is eliminated by the 
chemistry of plants, to be tarther sorted for uiau's use in the 
bodies of animals. We thus see how significant and literally 
true is the terra we apply to the earth of our gi-eat mother.' 

The nitrogenized bodies, albumen, flhriii, casein, and gluten, 
are also called mitritire and hist.iiitiietic (tissue liuilding), 
since they are emjiloyed in uoun'shln'J;!]! Uh- tisanes ..f t\\r sys- 
tem to a greater or less degree. Th^y niiiy lie dissolved with- 
out ditKeulty, and foniied into a Ihiid solution by di\ndiug 
them into small pieces, and keeping them for sevend hours in 
dilute hvdroL'Idorie aeid, the temperature of which is maintiun- 
ed stead'ily at 150° to 20n'. 

If to the mixture of aeid and nitrogenized substances a little 
jtepsin is added, the action then goes on at a temperature of 
100" as rapidly as at ^00° without the pepsin ; from which we 
conclude that the ferment imjiressea some change on nitrogen- 
ized substances, Avhich enables the acid to dis.solve them at a 
tein[)erature a» low as that of the stomach, viz., 102° to 104". 

Butter and sugar form a very considerable i>ortion of the 
solid constituents of milk. They are conifKised of hydrc^en, 
carlxm, and oxygen, and do not contain nitrogen; they are 
theretoi'e deserilied as non-nitvogeiiized hodies. They are em- 
]>loyed in the system as condnistihles, hy the burning of which 
the animal heat can be maintained^; consequently they are oft- 
en spoken of as ealorifacient g^esDirator^bod. 

Tne nou nitrogenized bodies are sulKlivi(ie{l into t\vo classes, 
owing to the difference in the quantity of the elements they 
contain : and since the subdivision has a practical value in the 
study of the digestion of respiratory substances, we shall de- 
vote a few lines to its consideration. 

Butter, fat, and all oily Ijodies contain an enormous amount 
of carbon, hydrogen, and but veiy little oxygen ; they are 
therefore called hydro-carbons, and constitute the first subdi- 
vision. The amount of oxygen they contain being so small, 



WhBl tilhcT nHm"s flvc give 


n lo tlie niirngpniiipd Kfunp? Utiiv nmv nftrogc'niici! mib- 


tltmeen l>c Jisnolv.'ii ? At »! 


tu tomrx-rntiira? Iluw .Iocs pni.sin Inli.ien<-e Ihe tirti»nr 


Wlmt »uliM«nccs form the noi 






uns t Whm arc the iKKuliariiiw yf ibe hydro-ciirboni ? 



NATURE OF FERMENTATION. 



they can in a given weight furnish a fai- greater amount i 
lieat during their combustion in the body than can be obtaint 
fi'om the same \veight of sugar. 

Sugar, starch, guni, and similar substances contain hydrogen 
and oxygen in equal proportions, so that the hydrogen may' 
regarded as nselesp, since it is already united with as mu« 
o.yygen as it has affinity tor, and tlie carbon only is availabl< 
for the production of heat. The proiKirtion of carbon in thi 
gi'oup is also very small, the number of atoms being aboui 
etpial to the number of atoms of hydrogen, Owing to the pro 
portions in which the constituents e.xist, it has received th« 
name of the carljo-hydrate division. 

If sugar is mixed with saliva, and kept at a tempei'ature of 
100°, it imdergoes a change, the sugar gi'adually disapjiearina 
and lactic acid taking its place. Starch altio luidergoes ~ 
change when brought in contact with saliva, fii-st l>eing cc 
vei-ted into glucose, a species of sugar, and finally into lactii 
acid. These changes are due to the action of the ptyaline of 
the saliva, and belong to the class of phenomena included un- 
der the head of fermentation, the study i.>f wliicli is neces.sary 
in order to understand the digestion of the ciirbo-hydrates. 

Fennentation is not only of interest in connection with thi 
mere act of digestion of i?tarch and sngar, but, since it lies al 
the basis of sucli oj)erations as bread-making and wine-makinj 
it becomes doubly interesting to the student. 

In onler to produce the fennentatitju of sugar, a solution o£ 
the substance should be mingled witli some suitable decayiua 
nitrogenized femient. Nothing answers the purjiose bett(« 
than yeast. Placing such a mixture in a cool place, where tht 
temperature does not rise above 70°, it after a while takes oi 
an internal movement, attended by the evolution of a consid^ 
able amount of gas. 

If the gas is collected, and examined by suitable tests, it 
found to Ik; comijosed i>f carbonic acid; and if the liquid 11 
submitted to distillation after the femientatiun has ceased, it ' 
found to contain a large quantity of alcohol. This is the cai ^^ 
BO long as the temperature is kept below TO" ; if it is allovrei 
to rise above that degi'ee, and appi-oach 90' or 100°, carbon' 
acid and alcohol are no longer pi-oduced, but lactic acid taki 

Wlml itiilHlancoi fonn the cHrho-liydrale group? Whnt are thcii' ]Hi-iiliai'Iii'^? WiTi 
Kmiip nf resiTinitory food riirni^lie* tlie grpu(e*t nniomit of lieni? WIml in llip apiion ■■fi 
livii on viik'Br — on Mnrcli? Wlinl is tlic csu>c uftlio BEtion ? Upon nlmi npiiiin du ni 
nn<l brcnd milking ilcpriiJ? DfiTiiUi ilie formenutinn of suimr nt 7iP. Wlmt gu 
orrilTi'il ni iliis li'iTiprrniiirc ? Wlmi it [iroiluccd beiiilia carbunic nviilf Wlist u« t 
pnxJiiclB when sugar fcrntenls ubuvu 70° F 






INFLUESCE OF TEMPERATURE ON FERMENTATION. 00 

tlieir place. Temperature, tLerefore, has a controlling influence 
over the fermentation of sugar, and decides whether it shall 
undergo the lactic or tlie alcoholic fermentation. 

Fmni the above facts, we see ivhy it is that the wine-maker 
resorts to the use of undergroimd cool vaults in carrying on 
his business; he knows that if the temperature should even 
for a short time nse above a certain degree, the M'liole vat of 
juice would be lost, and viiiegar produced instead of wine. 

In the feniiciitatioii ..f stiiri'li tlie I'lU'ct <jf toniperature is as - 
marked jts in tin. ..■a.<c nf^ui^ar; lnn htrtlv m-'ul J s produced bq> -^ .. 

^w 70^. and Mln.hu] :md .-avhuuK- add abu vt. rOT. 3-iv •PL^MJH 

. Starcli is nint;uni-<l in ail vam-ties oftlour, as may be readily 
i*hown liy takiiifi a sniall iiuantity and making it into dough 
"by the atidition of a little water. If the muM.s of dough i.^ then 
kneaded under the siiiface of water, a fine powder is slowly 
wjislied out, which ninks to the bottom of the vessel, and a te- 
nacious mass remains in the hand, which is the gluten of the 
flour. 

In the making of bread a certain degree of jxtrosity is to be 
obtained, which renders it more digeatilde. This is accom- 
plished by forcing the staix-h to undergo fennentation, the pro 
cess consisting in taking a given ([uantity of flour, mL\iug it 
with water and yeast, and setting it aside in a warm place un- 
til fermentation is thoroughly i-slulilished. More flour is then 
added, the mass uorkfd u|>, ilividcd, and set aside for the fer- 
mentation to continue tor a short time; it is then placed in an 
oven at a temperature of ahout 4(M)°. The high temperature 
stops the fermentation, and is applied long enough to drive off 
the excess of water and the alcohol that has been produced. 
The bread is then said to be baked. ■!. 

•'if the tempiTuture .)t the dough is allowed to fall below 70lk 
fthe lactic tViiueiitatloii sets in, and the bread turns sour. It is' 
then uutit for use, since mastication converts it into a paste, the 
interior of wliich the digtistive juices can not penetrate. 

In the Kensington Museum there Is a cjise containing differ- 
ent varieties of hread. which presents some facts of interest. 
Aniou'j the specimens e.vhil'ited there is a loaf of ordinaiy fer- 
nn'uted bread, two years old, which is converted into a mass of 
green fungus, while the .samples of unferinented bread of the 
same i^e are perfectly fi-ee from any such gfo^vtli. 

In tlip same case there are B[)ecimpns of New Zenland bread 



I will 
ritio 



WliRt Hre ll>c iimdiitto nf r^i-nienl.it.((in »r »mrrli »tH>iv nn<l Ik'Iow 711°:' Wliiil 
Itionof floiir ? Drwrilw llio i-licniiMry of limiHl-miikmK. Wlint ia oecom}ilit 
bread? WI17 must ihc tloueh Ui kci^t in a wurm jiluve? 



S6 GASTRIC DIGESTION. 

made of the pollen of a reed ; also Dlka bread, from Afi'ica, 
wliieli lias the appearanee of Castile soajj when cut. Thisrc; is 
also a specimen, said to have Iwen found in Lake Zurich, and 
BUpposea to Wloug to the stone period, hut there arc doulits 
regarding its history. 

fhe salts are phosphate of lime and chloride of sodium, or 
common salt, llie fii-st is eniployeil in the mitritioii of the 
hones, and the second, as we have seen, is essential to the prop- 
er eondtiction of digestion, furnishing hydmchlorie acid fur the 
gastric juice, and soda for the bile and pancreatic tiuid. 



LECTURE XII. 

DIOEJJTln.X. 

Miitticatlou. — Action of Saliva. — Action of Gastric Suiee. — Farmattun 

and Propftti^ of Cliyme and Vliyle. — Action of Pancreiitic Ji/iee on 

Sydro-earbont and Carbo-fiydrateg. — Oiil mid neie ThturU» of fjigtf 

lion.—Dige9tibility of varioua AnieUs of Food.— Effect of (jiiuHtiltf on 

the Rate of DigeMiott. — IndigeMiott at a Diaease and a /Synijttom. — JB^ 

feet of Nature of Diet on Length of Intestine. — I/igative Ap/iaralue m 

certamAnimals. r, Cy ^Xl^^ ^^l^WJ^^*^^(tjhAl£U4^ 

IIavino described the digestive apparatus, and examined, 

into the nature of the ingesta and digestive juices, we new piuta 

to the detailed explanation of the prm-esses to ivhieh the i'nnd 

is subjected before it is properly prepared fui- absorption by 

the blood -vesselft and lacteals. 

The first operation to which it is submitted is ninstieatioDf 
during which it is not only thoj-oughly subdivided, but hIbo 
mixed with saliva and air. It is then swalloui-d, and, passing 
into the stomach, the i)tyaline of the saliva coiiiniences immedi- 
ately at the existing temi)enitniv to eonvt-rt staK-h intu phicoso 
or sugar, and then inin l;i<|if mid. While this is goiiifi vn in 
the interior of the nuiss. tlif L'ustrie juice is acting with eiit-rify 
on its exterior, tlic hydrochlurii.' lu-id.liy the aid uf the jiepmni 
dissolving the nilioi.'cnizi-il eiibstiin<r^. iill)umen, fibrin, eaafeiB, 
and i^lutL'ii.eonverliiig tln'in into miIuMc nepti'nes Gradually, 
by the agency of tin- sjdiv;i and L^ji-^tiic jnu-f. ihe mass is Itroliea 
up, and a fluid called eliyme produced, which is of a tawiiy yel-. 
loiv color, and contains ihe ods and futs uiidissolvfd, 

Wlini imlic uwiiri>liiw|>li'itvi>rUiTi('? 1 
' ' lorn? Wh*i i> apcomplUhnl bj- 

^'hi-ro ii iti Mtluri curtW on t What an 





DUODENAL DIGESTION. 57 

The saliva is indirectly very efficient in promoting true gas- 
trio (ligestiiin, that is, in dissolving euhstanees of the nutritive 
group : tor the product of its action on starch and sn^a^ is lac- 
tic acid, whifh attacks and dissolves nitTOgeuized bodies almost 
a-* readily as hydrochlonc acid. While, therefore, the acid of 
the ga-itric juice is acting on the exterior of the mass in the 
stntii:H-!i, the lactic acid, which is being continually produced in 
its iutfrior, is also assisting In the fonnatinn of a solution. 

In persons who swallow their food without proper niastiea- 
tion.the saliva is not thoi'ou^dily miuL^led with it, consecjueittly 
lai'tic acid is not formed in sutticient ipiantity : the wliole duty 
of ga-^tric digestion is thrown on the gastric juice; it takes a 
longer time to accomplish the solution of the food, and the \)ei'- 
son suffers fi-oni an indigestion for which there is no cause Itut 
indoleuce, unless the teeth are so imperfect that mastication 
ciin not be properly peifonned. 

From the stomach the chyme oozes little by little through 
the pyloric valve into the duodenum, whei-e it meets the pan- 
creatic tluid and Iiilc, and quickly, under their influence, lie- 
comes converted into a milky fluid, to which the name of chyle 
is given. 

Cliylification consists in converting the oils and fats into an 
emulsion, so that they can be dissolved or suaiiended in water. 
If sod;i Is added to any fatty substance in sufficient quantity, it 
iiiiitr^ with it to form a soap, in which state it is soluble in wa- 
ter; !mt the pancreatic fluid contains albumen as well as soda, 
ami eacli minute globule into which the oil or tat has been di- 
vided by the soila is covered with an exti-emely thin layer or 
covering of albumen, forming an emulsion, in which cumiition 
the fat can be introtluced into the absoi-ptive mechanism, and 
finall}' reach the blood. 

Pancreatic juice not only converts the fats and oils into an 
emulsion, but It also acts on starch and sugar with even great- 
er energy than saliva, its pancreatine forcing thera to iindei^ 
the lactic fermentatinn with gi-eat rapidity. Owing to this 
property of the pancreatic fluid, nearly all the paiticles of 
staivh or sugar that have escaped the action of saliva are di- 
gested by pancreatic juice, and converted into lactic acid in 
such (piantity that the alkaline reaction of the fluids of the 
duodenum is lost when the lower part of the small intestine is 

ml is llio effi'cl of liollinK llie fiinil ? Wticm 

? Whnt i» mcanl bv chjli Oration ? Whiil 

I emulsion nnd a aonii ? What is the action of psncreMic Juice 




58 TRUE NATURE OP TIIE DWESTR^E PROCESS. 

reached, an acid reaction taking its plai-e, and continuing] 
throughout the large intestine. 

Tlif juici's uf the intestiniil glands m-e acid in their reaction. 
The mixed jiiia' containe a femieut, probably derived from the 
follicles of Lleberkuhn ; it acts on nitrogenizcd bodies, diRsoIv- 
ing them with ease, and" completes tlie digestion of those por- 
tions of nutritive food which have escaped the action of the 
gastric juice in the stomach. 

The above account of digestion is now generally accejjteil as 
the true explanation of tliat function. Among the various 
opinions that have been hehl regarding it, we may mention the 
mechanical hypothesis which wujtpused that the food was dis- 
solved by a stjecies of griiiiling t-peiation )iy the «alls of the 
stomach. This waa finally uveilhrown in favor of tlie chem- 
ists by taking various articles and shutting them up in ppher- 
ical suver balls, the walls of which were peiforafed, to allow 
the gastric juice free access to theii" contentn. On introducing 
them into the stuiunchs of dogs, and withdi-awing theiu fi-r)m 
time to time, and examining their condition, it was fonntl tlint 
the contents of the spheres wem slowly <lissolved, showing 
that mechanical action was not essential, though it might a». 
sist digestion. 

Every person knows, by his o\vn e,vi)erience and by the 
etatcnieiits of friends, that certain articles of food are more 
readilv digested than others. The comparative digestibility 
of ordinary articles was detennined by Dr. Beaumont, who had 
a patient, Alexis St. Martin, in whose abdomen there was an 
o|ieiiiiig tlijit communicated with the stomach, and which was 
the residt of a gun-shot wound. 

Heaumont states that when the stomach was empty, the niU' 
cous nuiiibrane was of a pale color; but when food was intro 
duced, it inunediately assumed a bright pink tint, owing to tie 
congestion of the blood-vessels, and in a few momenta the 
mouths of the fullicles were maiked by small lucid points, 
caused by the flow of gastric juice. 

The gastric juice exude<l with equal fi-eedom both when the 
food was introduced by the month or by the opening in the 
abdominal walls through which the observations were made. 

WIiM ii ihe renclion in Iho upper and Idirer pnitsarihc inrcsiinc? Whai UlboTcaniett' 
i>rili(! inlGttiniil juircif Wlmi iln ihcT ncmmplUKF Whm irns rhe olJ iliconr rrsai^hiit 
<lii:c*iion? I[<>w wM I lid morliMTiiFnl ihcnty ^nymveii, and the chemiml pftiibliaiinl f HuW' 
HTiu ilic •lige'libiliiv of vnrioiiii iiilMonrpa dplrmiinrd T Wlmt i« iliir rnlor nt Ihe gnMiie no- 
emK mdiihrane beforp Mid nfrrr ilio imrwdoctioii offooil? Wlinl is Iha appeonnre prtatiu-. 
eU bj llie muuihi oriho follicletf 



KEI,ATI\'E DIGESTIBIUIT Of VARIOUS ARTICLE:*. 59 

If the following table, furnished by Beaumont, is carefully 
exatnineil,it will be noticed that the method of cooking also in- 
fluences the rate of digestion, fried articles being more indigest- 
ible than those which are roasted or boiled. 



Tatite sluiioing the Time required fur the Digtstion of various AriicUt. 

h.m\ li.n 

lipiilos, (weet, rmr 1 30 Milk, boilcJ 8 01 

" sour, mellow, rn* 200| " raw 3 ll 

I^int, pod, builcd S 3() Mution, fi-esh^roui S II 
-B--«f, rresli, rure, rauiwiL SOOj ■' " hmileiA 8 IN 



IApiilos, (weet, rmr 1 30 Milk, boilcJ 8 00 
*■ sour, mellow, raw 200| " raw 3 IfS 
Bennt, pod, builcd S 3() Mution, fi-esh^roui S in 
-.B--«f, rresli, rure, rauiwiL SOOj ■' " /broUedl 8 00 
" drr. " 330| ■• " Iboiled/ 800 
■■ •■ ttird 4 OOOj-Blen, rrahrraw.* 'i BS 
Baati.boil«d 3*5j " " roasf 8 15 
Bn-nil, whQ.u, fresh bnkod 3 3ol '• " mcv/ SSO 

" corn, " •■ B IG Pannijw, boili-d SSO 

Riltwi-, melted 3 SO'Pork, (kt nnil lunii, rouKi 5 15 

lfC«bhngn with vineg«r, tbw 2 00| " " broiled 8 IB 

boiled .-..4 80 " " niw 8 OO 

CatllBh, frioil a SO Pouttocs, Iri>ih,l>oile<L 3 8oT 

I Cheese, old, sirong, raw .,, 3 SCi " " [bnki^ •! 80^ 

J- Codfish, oorod <iry, boiled 2 00 Kice, boiled....' ?, 1 00 

~ rn, gtvcn, itnd baani, bailed S45'SKgo, " 145 

_ M]inl. tMkciI 3 4S|Sali))on, Mllcd. boiled 4 00 

IQacka, JomeBlic, routed. 4 IIO Soap, licnf, rcgetnble 4 00 

" wild, rossted 4 30 " cliitkun, Uiilcd 300 

l-Bggn. frp'h, hnrd boikJ 8 30l " ovrter. IjoIIwI 8 30 

»>fi '■ 3 OOiTapiocn. boilnl 2 00 

friod 3 80Trlpe,H>tl«cd, boiled 100 

)iind?r, Treah, fried 3 OOlTront, salmon, frctli, boiled or fri^d I iHI 

n*l, boltod 4 OOTurkcj, domesiir, ruosl. S 80 

" rowt 4 00 " wild,r(iiuit , 2 IB 

frlMssMd 3 4r.TumTiii, boiled , S30 

iCroMI 3 00 Venl. fresh, broiled 4 00 

inb,rre«h. boiled 3 30 " '■ fried 4 80 

r, beef, boiled 2 00 Venison steak, broiled 1 85 

The rate of digestion depends on the quantity sa well as the 
quality of the food, for Beaumont found that while one egg was 
digested in one hour, it required four hours to digest eight 
^H]<gg». The digestion of soups is often very imperfect unless 
^^nbey are mixed with some such substance as bread, to retain 
^H^liem in the stomach, and prevent their passage into the duode- 
^^■lam until they are properly prepared for absorption. 
^H We can not leave the consitleratiou of tlie function of diges- 
^Vfcton without making a few remarks on indigestion, that most 
^^ohscure of maladies. If we examine any of the works on hy- 
giene, we find them stored with very valuable information re- 
garding the manner in which indigestion is to be prevented. 
Among these there are careful directions regarding tiie articles 
which persons so troubled should avoid. But I have found, in 
a hospital experience of more than two yeaw, that such rules 



60 CAUSES OF INDIGESTION. 

can not be estahlished, for some patienta would digest with 
ease articles which ivere considereu the most indigestible, and 
which would give an attack of colic to any hemthT person, 
while a meal of substances usually regaixlod as \ery uigestible 
would suljject them to hours of tortni'e. 

Some physiologists advise that the water introduced into the 
system should always have a temperatui-e ajiproachiu^' that of 
tne stomach ; but It is almost impossilile to tbilow such a plan, 
especially wheu ive recall the nauseating etJ'ect of wami water 
on the majority of people. We must therefore set aside all 
such arbitrarj' rules, aud each person must decide for himself 
regarding the articles liest adapted to bis own peculiar di<rest- 
ive powers, and the tempeniture at which they are taken. 

The food should be sufficient in quantify aud thomughly 
masticated, for if the stomach is overloaded it can not do ite 
work properly. It is no <lonbt wise, when a person has coni' 
maud of his own time, to abtitnin from mental or phy^eal exer- 
tion for a short period iifter eating. But how few will abstain 
from either, and, even if the}' dn, they are apt to become mor- 
bidly carefiil, au<l,in their aii.\icty to obtain jieifect health, ren- 
der their own aud the lives of those who come in contact with 
them insupportable. 

Indigestion is often a symptom of some disease, such as an 
impei-fect ]»riidu('tii>n of pepsin or hydixK-hlnrie acid by the 
gastric I'olliilc ^: Mich oases may be relieved by the use of the 
missing CDii'-titucnts of the gastric juice as nu-dicines. Regur- 
gitatitui <if bilr or ]nmcreatic juice from the duodenum into the 
stoniiich will ;dsii |>roduce indigestion, by neutralizing the acid 
of tlie gastric juice. Cancer, and many other diseases, the con- 
sideration of which wc have not the space to review, also seri- 
ously interfere ^nth the digestive pi-ocess. 

Tliei-e are ])eculiaritie8 in the digestive apjiaratus of some 
j.^ ^ animals which are of 

interest to the phj-si- 
ologist. An excellent 
example is afforded 
by ruminants, _^/jf. 64, 
which possess four 
stomachs, called the 
inghnnes, or moisten- 
ing stomach, ft, which 

Ilow are tho dlRpslivp powri-n'f t (wrwin to bo dctcntiiniMlT Of wlial •tiwasn b [niligc*- 
linn It nvTnmnm ? How i« dpfldcnnr of pc{iBin M be trMted T Uan docs icgnrsitstion of 
bile act F Kame ihn xomachiiof ihc raw. . 




I 




I 

Iwei 



KELATION OF FOOD TO LENGTH OF INTESTINE. Gl 

receives the food from the (esophagus, a ; second, the honey- 
comb, or second moistening pouvh, c, from M'hieh the ft>o<:l is 
sent to the mouth, to he again chewed as the cud, and letiirned 
to the thu-d stomach, called the 
omasum, (/, from which it passes 
into the fourth stomach, e, and final- 
ly escapes at the ]>ylorus, /'. In the 
porcupine there are also tbur stom- 
achs, while in the kangaiou there 
are eight of these organs. 

The nature of the food has a 
close relation to the di.iincter of 
the digestive apparatus, especially 
as regards its length. In the car- 
nivora it is veiy short, being but little more than a straight 
tube. A comjilex elongated intestinal canal in such animals 
would be sujterfluous, for their food m so rich in nutritive ma- 
teiial, and so easily digested, that only a part of tlie canal 
would be used. 

In the herbivora, on the contrary, an enormous amount of 
ibod has to be digested, in order to obtain sutKcieut nutriment 
to satisfy the waut« of the animal. Not only is the bulk very 
great, but the nutritious parts are difficult of extraction; and re- 
quire a more c<)mj)!ex apjmratus than that needed for the so- 
lution of such concentrated footl as flesh ; consequently, the in- 
testinal canal is elongated, and in those animals that require a 
large quantity of nutriment, on account of their size, as the 
" ^atie elephant, the colon alone reaches a length of more than 

enty-six feet, while in tltus(; whose food contains a very small 
■proportion of nutrimeht, as the Arabian droraedaiy, which 
feeds on dry stubble, it reaches the enormous length of forty- 
bIx feet. 

In jPi^. 66, page 62, the cseca of the common fowl are repre- 
sented ; a being the oesophagus ; />, the ci-op, or insalivating 
pouch ; c, the stomach ; </, the gizzard, or nia.iticating pouch ; e, 
the liver; /i small intestine; y.the ca;ca; and /*,the cloaca. 

The digestive apparatus of bii-ds, as well as of animals, is in- 

ueuced by the nature of the food, the cassowary, which has a 

plentiful 8Upi)ly of highly nutritious food, having a colon one 

K>t in length, and two cseca, each six inches in length, while 

I WImt is tlie' relnlion of the food tn ihelcn(;lh of lhcditce<livc canni? Whsl Kri; lln- |>c- 
BlirviTics of ihp iiitr-alines of llio hi-rbiv«ra? Whiil is ihe IciiHlh of llie inlcBiiiiQ in [lio 
'Rphuil anddrotncclnry? Conipnro ihc Icncib otihe imestino in the cai^oivary nndilti: lo- 
Wh>t pans compose ihe digeaiive met uf birds ? 




COMPOSITION OK F.ECES. 

the ostrich, ^vliose food is scanty, and not 
vei^' imtritiouR, has a colon tbrty-five feet 
in length, and two cajca, each two feet 
nine inches long. 

We might mention many examples in 
the other kingiloms and oi-ders of ani- 
mal lite which would illustrate the rela- 
tions of food to tiie length and character 
of the digestive tract, but the instflnces 
furnished are as strong and convincing 
as any that could be presented ; we 
therefore pass to the examination of the 
processes employed in the separation of 
the soluble nutritious elements of the di- 

tested fotid from those which are iiisolu- 
le or eft'ete, and consequently of no use 
in the human system. 



LECTURE XIII. 

HESIDirES, CAPILLAHrrr, O.JMOPIS. 

Cvmpotition o/ Firrta. — Origin and Diunial Amount of Ftrvta. — Into- 
final tifUf*. — OipHhry Attraction.— Jixamiiiti and MepUtuation of 
CapiUnrif Attrartiim. — Diolyais. — Tlie Endotmutiieter. — ijidvsmoti*. — 
Exogmusis. — Ariiiin of Gum in the Kndogmoi)tttfr. 

Arsorptiox of the digested foo*! commences in the stomach, 
and wTitinvies throughout the intestinal canal to the anus, until 
all the nutritive matter i.s conveyed into the system, and noth- 
ing remains in the intestines but useless ivsidue, to which the 
name of faves is given. 

^Jpffx are conij»ose<l of, 1st. Cellulcwe, or the woody fibre of 
vegetables and grain, which, though it is digested by l)eavere 
ami many insect-s, and Is their chief article of food, is not acted 
on by the digestive juii-es of man and the great majority of 
animals; 2d.StaR'h gnuiules, which have escaped the' action 
l>oth of the saliva and the (vinen'atlo fluid ; ;Ul. Shreds of mus- 
cular fibre: 4th. Tlie c^^Miring matter of ihe bile, which has 
l»ecn derivwl fi»m the coloring matter of the MixkI, and con- 
tains a ctuisiderable amount ofinm; nth. Epithelium, from the 
intestinal mucous membrane, and the glands ivnnei-ted with 
the dige^ive appara tus. 

WbM It'ibecwpUitM oTIlKMr 



COMPOSITION OF INTESTINAL GASES. 63 

The diunial amount of dried fiecea Ir about one and one 
quarter ounces. The apparent quantity is much greatei-, but 
that is easily accounted for when we consider the large pi'opor- 
tion of water they contain when freshly voided. 

With the fieces certain gases pass from the intestine. They 
are, 1st. Nitrogen, derived frcmi the air that was mixed with 
the food during mastication and swallowed ; 2d. Carbonic acid, 
derived in part fi'oih the bIot>d, and in part fi-om the partial 
decomposition of the food during digestion ; 3d. SulphuivLtHd 
bthI yl i osulniretted hydroa'en. also formed by the decomposition 
of food, or secreted from the blood. They give to the gaseous 
dischaiges of the intestine their disagreeable odor. 

In order to study the phenomena of absorption in an intelli- 
gent manner, we must lii'st examine into the nature of certain 
physical forces by lueans of which it is accomplished. The 
physiologists of olden times regarded tlie pyloric valve with 
peculiar interest, tor they thought that it presided over this 
function, and determineti what articles should be introduced 
into the system, and what shouhl be ejected as fteces. By the 
light which modem science and patient, painstaking examina- 
tion and experiment have thrown on this function, we now see 
clearly what the true nature of absorption is, and reason con- 
cerning it just as we ivould regarding any ordinary manufac- 
turing process. 

The toi-ce called into play during the act of absorption, both 
in plants and animals, is catiilla i'v at^r^^yt^|)D. by which is meant 



I the [lower tubes of nunt)W calibre possess oi raising a liquid 
above its proper level when they are placed in it. 

It may be illustrated by heatina; a piece of thermometer tu>)e 
vmv its centi-e, and turning it while it is in the flame so that it 
may receive the heat eipially on all sides. When it has at- 
tained a bright red lieat it is drawn out, and a jiei-fect tube 
'Slier than a uair is obtained, which, being touched to a drop of 
(rater, raises it to a considerable height 
The height to wliieh a tube can raise a litjuiil depends on 
■the diameter of its Xmre, as may l>e illustrated by placing in 
water tubes of diameters vaiying from half an inch to the 
finest that can be made, when it is found that the finer the 
_tul}e the greater the height to wdiicli it can raise the liquid. 
All liquids are nt)t raised by tubes of glass, Vnit some, such 



[ WliBlis thadiurnnlnnionntof r^ccB? 

What WHS ihc old iden rccurdln 

^hat determines ihc hcighl to n liicti a 




n»? Whiiii.ilidr.T- 




CAPILLARY ATTRACTION. 

as mercury, are depressed. If 
tlie fiuiii rises we say that it 
is by virtue of tlie pmperty it 
possesses of wettiog the tube; 
and since different fluids pos- 
sess this power to difftJix-iit de- 
grees, it soinetiiues secnis as 
though the tubes possessed an 
inherent power of selection, per- 
mitting a passage to ftotncfluids 
and denying it to others. 
-.;«,„» u"i«.u. '^'"^ selecting power, as it is 

commonly called, can be con- 
trolled liy very simple physical causes. For exaraplf, if w« 
take a bundle of ordinary lamp-wick and moisten it with 
water, and then dip it into a mixture of oil aud water, the 
latter %vill rise, but the oil will not. If we perform the e3E- 
perinient by fii-st wetting the wick with oil, the oil will rise 
and the water will be left behind. 

Though a capillary tube can lie jtrepared in such n iiiaiiiier 
as to raise a specified liquid, it can not establish a continuous 
flow through Its interior when it is broken off short of the 
point to which it raises the litpiid. The fluiil, under such cir- 
cumstances, meiely rises to the broken extremity of the tube, 
and remains stationaiy. 

If we take measures to remove the liquid from the broken 
extremity as fast as it rises, either by means of a piece of 
blotting-paper, or by evaporation, combuftion, or any other 
suitable method, the fluid in the tube will rise to take the 
place of that which is removed, and a current can so be estab> 
lished. 

The statement mnde in the previous paragraph may also be 
applied to membranes. "When these are formed into a sac or 
bag, and filled with a liquid which can wet its pores, the fluid 
quickly permeates the membranous bari-ier ; and it" it is re- 
moved as fast as it reaches the opposite side, the receptacle 
will soon become empty. 

This property is now applied in some manufacturing opera- 
tions to the separation of fluids from each other, by placiog 
them on the opposite sides of a membrane, and adjusting the, 



II hj the wlectme power of liibei? Gire lomis exmntilaa. Will liqaids taw 
™i^ »hon cnpillflrf tubes? Under whnt cirvumEHnnrei oan continooBa mt- 
hed ill tube*? IIov do ntcmbraneii act on liqiiiil»? Upon what 
icnt depend ? How ii this principle emplojed in mniiuraGiiirM t 




THE ENDOSMOMiTER. 



conditions necessary to produce tlie desired i-esidt It is de- 
scribed in cliemifnl woiks as the method hy dialysis. 

To illustnite tilt! action of jwrons niemhnines, take a mixture 
nf alcohol and water, jilnce it in a bladder-, and suspend it iii a 
omrent of air. Tim water in the niixtuie quickly wets the 
bladdei', passes tliroiigli and is evaporated from the exterior 
siirliice of the membrane, while the alcohol, having little affinity 
for the membiannus structure, remains in the V>ladder, and is 
finally so perfectly freed from water aa to be almost absolute 
or pure. 

Another illustration is offered by the experiment represented 
in the adjoining figure. The apj>ara- p^ ^^ 

tus is caileii an enih>smonieter, and 
consists of a small bladdei' filled with 
.ilcohol, and attached Mater-tight to 
a narrow tube two or three feet in 
length, and placed in a lai'ce vessel 
of jmre water. The watej-, having a 
great affinity for the membrane, pass^ 
es through it, but, as soon as it reaches 
the interior surface of the bladder, it 
is dissolved away by the alcohol; at 
the same time, the alcohol moves in 
the opposite direction, viz,, to the ex- 
terior of the bladder, and is in its turn 
dissolved by tiiw water on the out- 
side; l>ut as the water wets the liladder better than the al- 
cohol, it passes through its textui-e more rapidly, and conse- 
quently there is an accumulation of liquid in tlie intei'ior of the 
bladder; this is at once relieved by the flnid rising in the tube, 
and finally reachitrg the upper extremity, \vliere it forms large 
drops, and may be collected in considei'able quantity as it falls, 

it must not be supposed that the movement of the alcohol 
into the water, eH(A)8my«8, as it is called, will go on for an in- 
definite period, for it has a limit, winch is reached as soon as 
tlie liquid in the interior anti that on the exterior of the blad- 
der are composed of equal proportions of alcohol and water; 
it then ceases, and can only be renewed by adding more alco- 
hol to the contents of the bladder, or water to the liquid on its 
exterior. 




Ill)" mny niolinl he rnncpiilrnlej ? Deiici'ilie llio enibsiri'imcler. Uow duea ihe eniloi- 
iDomeier iici? Wltei'c di>ea ilio liijiiiil uccmnulate wlien ilie bIcdIiuI U in the bladder? Uovr 
lung nill ilie cndognioii* continue? 

E 



66 



ABSORITION. 



If, iiisteail of placing alcohol in the inteiior, we place it o 
tile exterior of the bludder, anil fill it with water, the iiiov 
meiit still goes on, Imt it is in the outwaitl direction ; con* 
qneiitly, instead of there bein^ an acennuilntion of liquid in th« 
bladder, there is a loss; it becomes partially eiiiptv- Thil 
movement is called eTosmo^is, in con trad istiuction to that pre- 
viously describetl. 

Substituting: a solution of giira for the alcohol, we find it acta 
in the same manner. When it is placed in tlic bladder, anil 
the instrument is imniei'sed in water, endosmosis is produced; 
and when the arrangement is changed as descnbed in the last 
paragraph, there is exosmosis. 



LECTURE XIV. 



ABSORPTION. 






Mefhanitm of Afuorption in PUiuU — Faneiiotu of the various 1 

The a»cm!lmgS<iji. — Description of a VUlia. — LtirtfoU. — /ieegttat- 
hm ChtftL — TRtfriK-jr -Murf. — Stonuith Atisorjitiim. — lUlus or Intetti- 
nal AluHirytion, — Ai^ioH of Maenterie Gland*. — i^ed of DUeaee of 
Atvafntrric Glantt*. 

Coui'ARKD with the circulation in animals, that in plants is the 
more ivmarkable, since it is acconiplishe<l by osmotic action 
alone without the agency of a heart or other mechanical nuniiv 
ing oi-gan. In the Seciuoia Wellingtonia of the Sien-a Nevada 
the sap rises to a heiglit of four hundi-e<l and 6fty feet ,ibove 
the crtJiintl, and in an Australian eucalyptus to four hundred 
andei-rhty ftvt. 

To (i^nipivheiid the manner in whieh this ast<>nishing result 
is attained, it is necessary to e.\amine the structuiv of the parta 
by wliioh it is aceoniplislied. In eyoirei^ons nlant*. or those hav- 
ing a tnie Iwrk, the cireulalory priK-ess is almost entirely ttoii- 
fined to the new \V(hm1. or outernuist layer of wooil, called sap 
wooil or alburnum, ami to the inner layer nf the bark, called 
the lilter. At their junction these o«>nstitute the so-called 
cambium layer, which otnsists of younj; and forming cells, of 
which the innemuist ni-e being contiitually added to the wood, 
and the outermast to the Utrk. It is in tlie wood cells that the 



iIm Btnilwl t U>]« i(on> ilnnUitun in plant* coai|wn wHb thM in aoimab 1 




CmCPLATION IN PLANTS. 6" 

ascent of the sap usually takes place. These Professor Gray de- 
scribes US being elongated, and between one and two thou- 
sandths (but in pine wood sometimes two or three hun- 
dredths) of an inch in diameter. 

Wood cells, like other cells (at least when young and living), 
have no openings; eaeh h:i3 its own cavity, closed and indepen- 
dent. They do not form anything like a set of pipes evening 
one into another, so as to convey an unbroken stream of sap 
through the plant, in the way people generally suppose. The 
contents can pass from one cell to another only by getting 
through the partitions in some wny. So short are the individ- 
ual wood cells genei'ally, that to rise a foot in such a tree as 
the basswood, the sa]) must pass throtigh some two tliousand 
partitioHs. But although there are no holes (except by break- 
ing away when ohl) there are plenty of thiu places, which 
look like perforations, and thi'ough these the sap is readily 
transferred from one cell to another. This passage is facilitated 
by the relations of the thin places in tlie cells to each other, 
those of one cell corresponding exactly to those of the a<ljaeent 
cells. 

Passing from the stem to the root, the structure may be re- 
garded as being the same until the root tips are reached. These, 
according to Professor Gray,"are entirely composed of soft, new, 
and very thin-walled cellular tissue, formerly called spongioles; 
it is only further back that some wood cells and ducts are found. 
The moisture (and probably air also) presented to them is 
^^absorbed through the delicate walls, which, like those of the 
^BBells in the interior, are destitute of openings or sensible 

^B Exteriorly, in the air, plants terminate in leaves; "these consist 
^Bof both a wootiy and a cellular part. The woody part is thu 
framework of ribs and veins. These serve not only to strength- 
en the leaf, but also to bring in the ascending sap, and to 
flistribute it by veinleta throughout every part. The cellular 
part is the green pulp, and is nearly the same as the green 
layer of the bark; so that the leaf may lie properly enough 
regarded as a sort of exjianslon of the fibrous and green layers 
of the Iwirk. In most leaves the green pulp forms two princi- 
pal layers; the upper one facing the sky, and the undei' one 
facing the ground. Tlie upper side is constructed to bear the 
sunshine, and, if the leaf is turned, it twists itself so that the 




68 



THE VILLUS DESCItlBED. 



proper side receives the liglit." The iiioiatiire exhaled from tbi 
leaf escapes cliiefly from the under surface, by the stoniata i 
bi'eathiiig pnres. 

From M-lijit we have seen above, "plants have no general mp 
cplntion, like that of animals, through a system of vesstOs open 
ing into each other. In plants each living cell carries od a cin 
culatioii of its own, at least wlien young and active. What then 
makes tlie sap ascend to the leaves^ 

"To answer this question we must look to the leaves tbeiite 
selves. For (however it may be in the spring bt^fore the leaves 
are out) in a leafy plant or tree the snp is not foi-ced up from 
below, but is drawn np from above. Water evapoiatt-s from 
the leaves; it flies off into tlie nir as vapor, leaving b.-hind nil 
the earthy and organic matters, these not being volatile; tlie sap 
in the cells of the h":if, theit^fore, becomes denser, and so draws 
upon the more watery contents of the cells of the stalk, these 
upon those of the stem Itelow, and so on. fi-oni cell to c«ll, down 
to the roots, causing a flow from the roots to the leaves, which 
t>egiDs in tlie latter, just as a wind begins in the direction 
towards which it blows." 

Passing from plants to man, we find that the villus of the in- 
testine is the analogue of the spongiole of the plant; nndjui^t 
as the 8i>ongiole absorbs from the earth water and nutnment, 
so the villus, and also the blood-vessels of the gnstnc mucous 
membraue, absorb fi-om the digested food its nutiitive parts, 
and introduce them into the system. 

A villus is most readily described by commencing at the in* 
tenor and passing outward ; following this plan, we find in the 
inteiior the termination of a lacteal tnlie. which is a club-shaped 
lymphatic space: outside of this there is a layer of blood-vea- 



■V' .1 



VMM AMHtt TMWNMtiM ■< Ibt laNMl T«b* 



DMCfCh* iIm w w xr I* whk-h «)• uxm* (Vum ih« root i<|« i 




ABSORPTION IN ANIMALS. 




in Ins CiMnul CTUiutn))d EiiItlieKun. 

ncLt's in length. 



sels and niuacle-cells, co\ eretl 
t>y columnar orcylindroid ep- 
itlieliuni, which comes in con 
t)wt with the chyle formed in 
the inte^^tiiml canal during di 
gestion. 

From the villus the lacteil 
passes tlirou^h one or mine 
tnp<ijnti-j ri<' o -fiiTiils . and, unit 
iuy with other laoteals, tonus 
lai'pT and larger trunk*) 
which finally enter a lonj; 
tulie half an inch in diameter and four or fi' 
called the receptacKhim ihyh, whith lie-* 
on the luniliar veitebra-. ^ 

/ \ delicate tuhe, called the thoracic diirt, 
/passes tVora the upper extremity of the r 
( eeptaculum chyli, and.tiaieisiiiir the tho- 
racic cavity, empties intii tlie Id't suhcla- 
vian vein at its junction with the internal. 
jugular, as is shown in the figure, 1 lieiiig 
the arch of the aorta; 2, thoracic aorta; 
3, abdominal aorta ; 4, arteria innorainata ; 
i), left cai-otid; (J, left subclavian; 7, vena 
cava descendens; 8, vena) innominatte; i>, 
subclavian vein; 10, gi-eat vena azygos; 
11, lesser vena azygos; 12, recejitaculum 
chyli; 13, thoracic duct; 14, the curve of 
the thoracic duct ; lo,tbe right lymphatic 
duct. 

For convenience of description, the func- 
tion of absorjUion may be studied under 
two divisions: 1st. Stomach absorption; 
2d. Villus absorption. In the fii-st the 
veins of the stomach take ujj by endow - 
niosia the nutritive materiaU which have 
l)een converted into chyme by the action 
of the gastric juice; Buch bodies , there- 
fore, a-^ tilirii i. gfltiiip e g . c fl S (;i^ r a nd gluten 
enter d irrrily ii^to the blooil-ve^ls as s o on as they are di gested . 





fO ACTION OF Till: MESENTERIC GLANDS. 

Ill villus lihsoi'ptioii. on tlie contraiy, after the chyle has 
n'iU'lu'd tlie interiur of the lactciil tube, it is obliged to jiaas 
tliroufih tht> iiieseiiteric glands, wbit-h are counected with tliK 
lactt'iils. Betbie entering the glftiids the chyle is composed uf 
albumen nnd fat, but after it has passed thixmgh tliem it cud- 
j^j^ tains tibriii and lai^e nucleated celle, 

called cliyle corpuscles. 

These corpuscles are of gi-eat intei^ 
est. for they aiv the nintlier cells fi*om 
which blood discs luv boru. In chil- 
I dreu the mesputer ji- ^rlnndti are 4>ftea 
I disea!<ed, the peculiar substance called 
tubercle, which is formed in the lungs 
in consHniption, being dejxisited 
these glanas in very young persons 
Whenever this occurs, the function of 
the Etlanda is serioni-ly interfei-ed M-ith 
chvle cornnscles and fibrin' «r^ not prodm-.tl : the blood and 
muscles niv not ]>iii|H-r]y inmnshe*l. and the child is jiale ami 
emaciated ; ilH stit'iigtli grows less and less every day, until 
(Icalh su|H'rveiu's. 

l.ea\ iiii: the mcseiitem* gliuids, fsoiiie of the lacteals ei»ter the 
Veins of I lie intestines bvit the givat majority |m»sto the ivcep- 
tai'idurn chyli. so that the oils and fats follow a verv circuitous 
route befoiM t\w\ fiualK' etUcr the bliKxl. 




ehfl* cnpBwkK 



LECTURE XV. 

BUH>IX 



iVyvK.V* <>fS.i,K- Or' m.-i^t- r..r 



4 tAr AfpforoMM tff&eod, 

. r' ( V.j«.i/< OH iu Compo^ 



\\x pliuit!* and aiiiinali* |>(\«M<«!i a cimiUtiagntttritire fluid 
or juict' : in plants it i* c*llwi sap ; in aiiiuiabs bkk«l. The ool' 
or of tho Mutritivp fluid vari^^Sv Iving Atim^iuM$ whito.ai 






COMPOSITION OF BLOOD. 71 

en coloi'less; but in animals it is eifcLer a briglitor a dark red, 
according aa it is arterial or venous. When firet dra^Mi from 
a fi'ee opening, blood is always perfectly fluid ; but after it Las 
stood for a time a portion turns solid, funning a maas called a 
clot, which floats in the fluid part, to which the name of serum 
is given. While yet in the arteries and veins, the Idoud re- 
tains its fluidity, and consists of minute red cells, which float iil 
a tawny-colored liquid called plasma. 

Tlie total weight of blood in the system was determined by 
an extensive series of e.\j)eriiuents on decapitated criminals to 
be equal to yn^jlghjjj^ of the weight of the body. It is con- 
tinnally changing, since it is tlie channel through which the in- 
gesta are introduced into the system. The nature and extent 
of the change may be realized when we reflect that the total 
weight oi til is tluiil iu the body, according to the results of tlie 
expt^riineiit^ sjioktii of above, is less than twenty pounds, and 
the annual aiuoimt of ingesta is more than three thousand 
pounds. 

There are slight' variations in the nature of the circulating 
juice in the dift'erent sexes, the bUxxl of males being heavier 
than that of females. Climate also pmduces its influence, 
causing tliat of the inhabitants of tropical regions to be dark- 
er colored than that of pei-sons living m cold countries. In all 
animals it possesses an odor peculiar to each species; by add- 
ing a little sulphuric acid to a sample of blood obtained fi-om 
an unknown source, it gives out the peculiar odor of the ani- 
mal from whicli it was obtained, eiiabliiig us to determine its 
origin. 

The reaction of human blood is alkaline; and since it con- 
tains a considerable amount of nitrogenlzetl substances, it is 
veiy prone to undergo decomposition, giving off a disagi-eeable 
putrid odor. 

I The substances which enter into the coiujHisition of blood 
are 



I 



Wnicr TH-t 

Albumen 71) 

Kiirncihe miil fni , (i.TT 

Bnlu.... 6.03 

Fibrin 2.20 

DisM I3MKI 



I Whnt iil ihp nppenrnnro of fnahh-ilran n blood ? How docn it rlinnire ? Wlint is ihe ni- 
f»I wcigiil of blood in llio boilj? How \vu» iHlKlerminevI ? la ilia i!opii|io»iiioii of llie lilurij 
dxeJ? Whnt U iIir influence of »px on the romimsi'lnn of Hood— of climHie? ilnw hkiy 
lliii odor ofhtoid uf diflcrenc nnimnl* lie rrolvcil f Wlmt i^ rbe rcaclion of bluod? Wlrnl 
b the conipoailion i>f LlooJ ? Whnt is plaamn ? 



72 



ORIGIN VV TIIK ALBUMEN, ESTltACTIVE, AND FAT. 



Water forms the l)a«is of thy fluid ; it is sultject to slight va- 
nations in quanfitv, tle])einJiiig ou its use. If it hiis beeu re- 
cently introduoed into the stomaeh, the propiirtiun may rise 
considerably above the figures in the tabh^; if it has not beeu 
taken for some time, the pei-ceutage will fall belo^v■ tho stand- 
ard quantity. 

The albumen is the representative of the nutritive group; 
out of it all the tissut's of the body are formed to a greater or 
less extent; it is derived from the albumen,fihrin, gluten, and 
casein which were inti'oiluced into the stomach as tbod. The 
constitution of these substances is almost identical, at lea.st as 
far as the number and character of atoms composing them Lt 
couceiTied. Their conversion into the albumen of tlie blooil is 
thei-efore very simple, and is j»robably accomplished by merely 
rean-auging their e<jmponent atoms so that tiiey are grouped in 
the same manner, and consequently out of sulistauces which 
possess different physical properties and qualities one homo- 
geneous material is formed. 

The extractive is a tenn applied to certain substances con- 
tained in bloixl, and nearly all the fluids and tissues of the 
body. It appears to be formed of a number of organic mate- 
rials, which give characteristic pi-operties, such as a detiuite 
color or odor, to the substances they compose. The extract- 
ives have as yet been examined only to a very slight extent, 
and but little is known concerning them. The proportion in 
the solid ingredients of some of the fluids of the body is ver\' 
large, and the study of this class of substances otfei-s a more 
pnmiising field of discovery to the physiologist than any other 
department of his scienqp. 

Fats are derived from the oily and fatty substances employ- 
ed as food; they belong to and represent the respiratory claae, 
and are used in the system to pmduce the heat which enables 
all animals to keep their temperature either above that of the 
medium iu which they live, or at some fixed degree. 

As has been already stated, the fats aie in part turned into 
sugar in the liver; in this state they are jjrobably more prone 
to undergo oxidation in the systemic and jmbiiomiry blood-ves- 
sels. Those portions which are not converted into sugar are 
stored sway in the cellulai" tissues of the body, and form the 
iat of the animal. 



Whni ia (he ftincti.m of wnUT in llm lil.Hjdf Mow mny iho 
Aon iitl>iiini-n irprrwnl ? From wlinl i* it ilcriTod T AVIint is tho 
rancrionuffntit What ia tha aciionoriho liTcron rmir 



FUNCTION OF THE SALTS IN THE BLOOD. 73 

Tlie most important salts ai-e chloride of sodium, phosphate 
of liiue, and phosphate of soda, 'Hie common wdt, or ohlonde 
«>f sDilium, is, as we have seen, used to fiiniish the liydvnrliloi'ic 
at'id iii'the gastric juice, and the soda of the Mle. Wlim the 
al.isorptinn of the digestive material is cmtipleted, tlie^^c liddic-s 
meet again in the general circulation, reunite, and fi>nii salt, 
which may be again decomposed to furnish another supply of 
acid and swla, A veiy small amount of salt can in this man- 
ner be caused to fm-nish an almost unlimited supply of digest- 
ive juices; and though man continually renews the salt in his 
system, there are many animals, such as the linfi'alo, wliith re- 
s<.>rt at a special season of the year to regions %vhere salt depot- 
its exist, and obtain a supply of that material which lasts for 
many months. 

Phosphate of lime is employed to nourish the lumea and 
teeth. In the eai'ly peritni of the life of an animal very hu^e 
snjiplies of this substance are required, and we find that milk 
contains a considerable proportion of bone pliosphate. The di- 
urnal amount of this phosphate in the milk of the mother is 
greater than that introduced into her system each day in her 
foml ; under these circumstances, the milk phosphates are de- 
rived fniiii the osseous tissues of the parent; consequently, 
din-iiig tiie muvingperiod, when the bones of the young are be- 
ing omsitliibited, those of the mother steadily lose phos])hate 
lit litiie, and tlie osseous tissues of the child are literally con- 
structed out iif those of the parent. 

Phosphate of soda presents one peculiaritj' v.bich is of gieat 
interest as regards the movement of carbonic acid gas in the 
body. If pure water is taken, it is tbund that at a given tem- 
perature and pressure it \vill absorb a definite volume of this 
gas ; but if to the water phosphate of soda is added, it then 
takes up a far larger volume of gas than it dissolved when in 
the pure condition. The presence of phosphate of soda in the 
blow! therefore enables it to dissolve and hold in solution all 
the carbonic acid evolved in the body. 

Though the filirin appears to V>e in such small projiortion, 
it is one of the most important ingredients. It possesses tlie 
power of sptmtaneous coagulation, and may be obtained by 
t ^whipping freshly-drai^Ti blood ^vith a bundle of twigs ; under 

t TPImt arc Iho talu in the binod ? For wlint pnrgiDan U Iho ciiloride of Kxliiiin em[>loypd ? 
ibn* M tha percentage of salt in Ihe blond miiinlniiici) ? Fur vhnl purpose i« llie phi)a]ihnlo 

if lime Ptnplojvd ? How is tba Inrpe pni)iortion of phruphnle of lime in ttia miik iibtuinod? 

iniHT. pnipcrtT docs Ihc iihoiplinto of soda imparl to the blood ? Iluiv maj fibrin ho obtain- 

d from blood'? 




coirposmoN OF THE clot. 

tliese circumstniioe?, the fibrin, as it coagulates, attathea itself 
to the twigs, and is obtained as a light yellow material in the^ 
form of a stringy mass. 

The elot jiroduued when blood coagidates ia comjtoswl of tlie' 
fibrin of the fluid, which, as it takes on the solid condition, 
forms a network of fibi-es in which the discs are entrapped. At 
fll-st the clot appears to ot-cupy the whole mass of the fluiil, 
hut, as soon as the fil)rin is coagulated, it commences to win- 
trai-t, and the size of the clot steadily diminisihcs until it is 
(piitc miiall and hard. The contraction j)f the fibriu iii the elot 
is_theJ5st lin,ng actof the b hKul . 

Fibriu is i>i-odaced in the system at the j-ate of .sixty-two 
gniin.'i JHT hour, luit the quantity in the blood is xinchaug<'d, 
since the muscles npprojiriate it as fast as it is formed. If 
ehj'lc is cxaniiued siter its passage ihi-ough the mosenteric 
glands or lymph, after it has ntren subjected to the action of 
the lymphatic glands, they are lM>th found to be very rich in 
filiriii, wiiih' alluimen has disappeared; we thei-efore eonclude 
that fibrin is pniduced out of alliumen by glandular action. 

The discs are shaped like a coin, be- 
ing cii'cidar and flat; they are niHUit 
sVini "f"*i'i '»t"l' 'u diameter, au'I rs^ 
tifnu inch thick. The cell wall nl'thu 
disc is composed of a substance catted 
aliJmUn ; the iulwriur fluid hAmmtx^ 
oin,\v\iKU contains n very lar^ amount 
of iron, and is of a deep i-ed color. 

If fit-shly-dniwn dark or venous b]oo«1 
is placitl under a j:ir cunt-:iiuing ojty- 
gi-n, it turns bright. Itecoming arterial. 
This chan^ is due to the discs alisorl>- 
*"S oxygen, the liaMuo^Iobin having nn affinity for that ga^ 
and yet not uniting \vith it, but i-ather dissolving it, to sur- 
r*'n*ler it up again. The union of o.\ygen with hH'niogl()t>in 
i* so weak that we m.ty rt-ailily scivmite them i>y placing the 
fluid under an aii^punip jar.and e.^hausting,M-hen tb« oxygea 
is inmtetliately set fi>i*. i 

In additit^i to (he nvl cttriuisoh* or discs, then- are Ifttve 




Ikt OixK. WiM H Ant *■««■««« } (V akM I* iMr 




% 



OlMOIN OF THK BLOOD DISCS. 73 

Spheroidal cells floating in tln^ Mood, winch differ from the I'ed 
dises nc)t only in color, Init also in their specifie gravity ; they 
move along in the current of the circulation in a tai'dy manner, 
seeming to cling to the walls of the capillaries and smaller 
I il(>f id- vessels, 

The white cells contain a nmnlier of nuclei, while the led 
discs do not have any nucleus, though at times they apjjear, 
under the microscope, to be nucleated ; but it is a deception 
produceil liy the ti^'ure of the disc, the sui-faees of whicli are 
nut i)erffct]y H;it,l!kt' those of a coin, but slightly curved, being 
sometimes concave and at othera convex. 

The red discs ori";inate from the white cells, to which the 
name of mother cells or corpuscles is given ; the method of 
pi-oduction is by rupture, the white corpuscles bursting or their 
walls dissolving, and the nuclei, being set fi'ec, assume the red 
tint, and become full-gro\\Ti led blood corpuscles. We may 
therefore say that the red discs are the nuclei of the white 
cells, and are set free when the mother cells are destroyed. 

ITie white cells, in their tuni, originate from chyle coi-pus- 
cles which were formed in the mesentenc glamU. When these 
glands are diseased, as is frequently the case in young children, 
the muscular and otlier tissues of the body become sol't, tlie 
bloo<l loses its color, and the lips and skin no longer prcRcnt 
the natnial rmldy hue of health. These changes are all due to 
tlie iact tliitt tile diseased gland fails to produce chyle corpus- 
cles with suihcient rapidity, and consequently the number of 
red discs in the body is greatly reduced. 

As we view the blood under the microscope, we find that it 
consists of separate discs floating in a fluid ; to this liquid the 
name of plasma is given. It contains all the other constituents 
of the bhiod, and differs from seruni in that the latter fluid has 
lost its fibrin duiing the formation of the clot. 

It has been estimated that twenty millions of red blood discs 

deatroywl in each pulsation of the heart, and there is every 

iD for believing that the estimate is conect. On this basis, 

man, in the course of eighty years, has created and destroyed 

in his system such a vast immber of millions of millions of 

"iese organisms, that if we were to place tliem side by side ko 

to touch each other, they would fonn a line long enough to 
around the earth more than ten thousand times. 

IJMcribf ttio wliite cells. Wlini is ihcir relation lo lira red diMs ? Wlint a ilie origin 
of the wliiic cg11i>! Why nrc the m! ilificB nidticcd In niiml>er in diH-aw orihe mincnlcric 
ginnda? Whnt is ihn difference betiTcun -,i'.agina and tcrnm? How niany discg are de- 
•irojed liy cnch pulsation of ilie litf«rt' 



7G THE CIRCULATORT SYSTEM. 

Astronomy has its wonders, and dismays us with distances 
which the mind of man can not gvasj), telling us that thoiigU 
light moves with a velocity ol'thouriunds of miles in a Becuiid. 
there are stars so far distant that th^-ir light does not r(.*ach the 
earth tor yeara after it is emitted by the star. Physiology also 
has its marvels ; and though the numlicr of Idood dist-s pro- 
duced in the system is almost incredilile, it fulls into insignifi- 
cance when we compare it with the total number of cells pro 
ducetl in the body during a lifetime. 



LECTURE XVL 

THE UEART, 

77ie Dicisiom of Blood-vessels. — TTteir Composition nnd Character. — Or- 
der of Development of the Jilood Syitem.—The JJeart deacrihed.- 3Jit 
Pericoi-dium and Endocardium. — Muscular TUstte tif tfie Heart. — Itt 
Cavities, tluir relative Position. — Itate of Pulsation. — Valves. — TReir 
Ptmctioa, — Vedvular Sounds. — Diseases of the Valves. 

From the consideration of the character and prnperties of 
the blood, we now pass to the study of the vessels in which it 
circulates. 

The blood-vessels are divided into tliive cla^iseft, viz., arteries, 
veins, and capillaries. The arteries have thick avails, and are 
i-mjity after death, their coat^ being s>o elastic as to enable them 
to retain thw clividnr tube-like form. Owing to this peculiar- 
ity, it was formerly supposed that they couveve*! air to all 
parts of the body. The veins, on the eontrari', liave such thia 
walls that thev e<illapse when empty; they are also provided 
with valves, ■\vKich open toward the heai1. The walls of botll 
arteries and veins are conipt>sed of three coats, an exterior lay- 
er of condensed cellular tissue, and an interior thin smooth 
membrane-. Between these there is a layer of elastic fibrous 
tissue, which contains involuntaiy muscle cella Some physiol- 

Z" ts si>eak of it as the museubtr o»at, while others tall it the 
tic eoat. 
When the arteries in the li^ ing Unly are cut, either by in- 
teutioD or awideut.the bhKKl flow^ fnun them in a strong in- 
termitting current, the impulses (H>rrespouding to the pnlsations 

Whd arc tlw ihnM tliisMi* i>rMiiiiil-<T«*rt>? What U ihe didcrvncc in B|ipcanuKR b»- 
tmetm ibe aitniM ami nint *A«r JmUi! T> wImi b ttin Aur.t What m* iIm> ibrve co^ 
(irUn«l-tt«vl*? Wbu b lli« ctuuMWr of iIh flow of blood Oom rein ud niniM vh^ 



THE HEART DESCRIBED. 77 

of the heart. Tlie only way to stop the flow from the large ar- 
teries is to tie them with a stout wilkeH striug ciilled a ligature. 
When a vein is cut the flow of l>U)od is dark red, that from 
the artery being crimson or aiterial. The nature of the flow 
also if* different, being continuous, and not possest-ing the jerk- 
iug character which marks the flow of Idood fix)m an artery. 

The large veins and arteries continue to suhdinde until the 
branches are so small as to escape ordinary vision. 'J'o these 
minute vessels the name of capillaiies is given ; they are about 
S(Mi5 of an inch in diameter, and constitute the channel of com- 
munication between the arteries and veins. 

If we watch the development of the blood system in the egg 
of a frog, or in any suitable embryo, we find that its fii'st rudi- 
ment consists of a mass orcells, of whieh the iimermost deli- 
quesce to form its cavity, while the outer constitute its walls. 
The first appearance of the heart in the chick is at aliout 
the twenty-seventh hour; the time of its formation in mam- 
mals is not known. 

The heart differa in its character in different creatiuTs: in 
some it contains a single chamber ; in oth- 
ers, two; in others, three; but in all the c*^^n 
animals of the class mammalia it contains I^^'' --v 
four cavities. 

In shape the heart resenddes a cone, br- 
ing four or five inches in length, and tliri-<' 
ur four in diameter at its base or liirL't- 
part. The size of the heart of any indi\ '■ 
ual is said t« be equal to the size of i i 
closed fist, but this estimate is of com ■ 
merely approxhuate, and liable to vii\ « , 

great error. It lies on its side in the tho- ^-^.^ 

racic cavity, across the median line, with .^^ 

the apex pointing downward and to the 
left, the base luing u|)permost, and on the right side of the 
atenium or breast-bone. 

' The heart is covered exteriorly by a stout fibro-serous mem- 
'ttme called the ])ericardium, which closely resembles the se- 
ns or synoWal membrane of joints; and when we remember 
i ligaments which form the joints, and the fibrous nature of 

V In be stDp]iei1 
ottlor of ilic ileiplnjin 
imabi? Wlinl i» iis : 
iiliciipi'x? Bjniiiil 






78 THE CAVITIES OF THE nEART. 

the perictirdiuni . it is not at all sui-jirising that rheumatism, a 
disease almost jiectiliar to joints, should ofteu attack the heart, 
the coustitutioii of which mi (.■losely reseuililes that of a j<»int. 

Tlie interior of the liciirt is liiu-d Iiv a serous membi-ane, the 
contimiatiuii of whicli iilsu forms the nnier layer or coat of the 
blood-vessels; it is called the endocai'diutu. 

The middle layer of tlie heart is coinposed of striated mus- 
cular tissue, arranged in l)auds, which ai'e very prominent in 
its interior, crossing each other in all directions. In man the 
ca\-ities are airanged in such a manner as to form two distin<'t 
hearts, each o? «hich is composed of two cavities, one at the 
base, the other at the ai>ex. The cavity at the a(>ex is called 
the ventricle ; it is conical ni ti.)mi. 

To the division of the heart which lies on the right side of 
that organ the name of the right heart is given ; it receives the 
dark venous blood from the great veins of the Ixxly, and i»ro- 
pels it to the lungs to be arterialized ; it is theretbre called by 
many authors the pulmonic heart. The left division is known 
as the left heart; and since it receives the cnmson arterial Ii1o<h1 
r,^ --_ fi'oin the lungs, and drives it thii»igh 

the great arteries of the system, it is 
called the systemic heart. 

In tiie dugong, the right or pulmo- 
nic heart is separateil fiom the left or 
systemic heart, as is illustrated in the 
figure. A is the aorta; D, ^he right 
auricle; E, the right ventricle; F,tlie 
pidmonaiy artery ; K, the left auri- 
cle; and L,the left ventricle. 

The two divisions of the heart are 
arranged so that the auricles lie side 
ii««tB(Ui.i.«ir«B. ijy 3i,1e, and form the base of the or- 

gan, while the ventricles are in a similar position at the apex. 
Since the auricles receive the blood sent to the organ, and 
empty it into the ventricles, acting as mete assistants to them, 
they are not required to exert any veiy great force; conse- 
quently their walls are very thin, being but little more than 
one eight ^ i of an inch in thickness. 

Tlie ventricles, on the contrai'y. and especially the left, force 

Whv is ifac hrnrt linlilo lo rhpiimniism? What i< ilm cmiocnrdiain ? Whnt liuno com- 
pow» ihe middle Inyer of llio wnll of Iho hpnn? Nmno ihc cnviii™ of ilie heart. Wbnt 
n limes n re Riven lo iho HbIiI eidp ofthn hcnrir Whai loihcU'fi? Wlint i»ihe rvlnlircpo. 
(iliim of tlio noriclc* And vcmrkirs? WhiH is the diiiv uf ibo miridi's? How tblck am 
their trnlUf 




THE VALVES OF THE HEART. 



79 



' Ii 

IS 
: 



|,the blood into the arteries, and deliver it to the capillaries ; 
Itheir walls, thei-eftii-e, are more substantial, that of the left, ven- 
Itricle being often M])- yy rp^^rtei-a of an inch thick. 
t It is estimated that the left ventricle contracts with Ji force 
f equal to 13 Ibi^., the pressure of the Itlood in the aorta, or great 
systemic artery which conveys the fiuid to the other arteries, 
being 4 lbs. 3 oz. 

The number of pulsations in a minute varies \vith the age of 

the individual, being 130 to 140 at birth, 80 to 85 during 

childhood, 70 to 75 iluring adult life, and 50 to 65 in old ao;e. 

It iy also more frequent in females than in males. If we make 

' due allowance for these vai'iations, and estimate the amount of 

t"tlood discharged by the ventricle into the aorta at three oimces, 

Iwe tind that at the age of eighty yeai-s the heart of a man has 

Imoved a mass of blood sufficiently large to build a column fif- 

mty feet stpiare at the base, and tweh'e hundred feet high. 

The auricles and ventricles are jirovided with valves which 
compel the blood to flow in a definite course — that is,ironi the 
auricle into the ventricle in each divifiiou. We may study 
thera to advantage in their proper order. The first \alve lies 

I in the right or pulmonic heart, between tin- aunele ami ventri- 
cle; it is composed of thive divisimis, w!iii.!i close the opening 
between the auricle and ventricle perfectly u hen they come in 
contact with each other. Tliis is called the trieusjiidjor three- 
Jipped valve. 
The second valve closes the 
opening between the right ven- 
tricle and the pulmonary artery 
which conveys the blood t'i'om the 

■heart to the lungs to be arterial- 
bed ; it is composed of three 
half-moon-shaped divisions, whicli 
meet when the valve is .sbuc. It 
is cidled the seniiliniar. 

In the adjoining figure, fi-om 

■yilaoa's anatomy, 1 is the right 
Unriele ; 2, its appendi.\ ; 3, vena 
eava descendens ; 4, vena cava as- 
eendena; 5, fossa ovalis; fj,Eu- Kii(i.isM.-ifihtiimrt. 

Wliich cnviiy of ihe liravi Iieu tho lliicke«[ waIU ? Whnt is rlic Turcc excrlctl liy ihc left 

nmricle? WhM 19 Llm premnra of iho Mood in tlie norU? Wlint i» ihe rate iif pnlsnti'm 

M binh — clilldliDod— adult life — oU n([c? Wlitit is ilio volume of Llond roovoU bj the 

^^Mtart inn lifetime? Wlinl ia tlii' dircciion Ihc vnlves furt-'a iho bloud tofulluw? Dcscribo 

^^Bhe flm rihe, its nomc, cumtKHition, poiition ; tlio iccond valve, iinmc, comjioiiiion, po^- 




jhi-* 



I 80 TIIE VALVES OF TIfE HEART. ^^M 

I atachian valve; 7, mouth of otironary vein ; 8, coronary valve; 
9, ftunfulo-vc'iitni'ulai' opening; a, right ventricle; i,(; eavitv 
I of ventricle ; (/, pulmonary artery ; f,/j tricuspid valve; </, tli'e 
I long columnR carnea ; //, the long moderator baud ; i, cnluniiiw 
I carnea* of tlie right cuitfiiu; /■, ^tendons: 7«, valve of pulii;o- 
I nary nrtery, or semilunar valve; n, apex of appendix; o, left 
I ventiicle; p, the ascending aorta; q, its arch; r, desceuding 
I aorta, 

I The function of the tricuspid valve is to prevent the Idcnxl 

flowing backward into the auricle after it has been fo]-ce<I into 

the ventricle, while the auricle is expanding and the ventricle 

contracting. The seniiUinar valves in the same manner close 

I the o]>ening into the jiulmonaiy ai-teiy, and prevent the blood 

' returning while the ventricle is expanding. 

In the systemic heart, the valve between the nuridc and ven- 

/,/tricIe is composed of two folds or divisions, and from it--^ fan- 

■T**V7ied resemblance to a bishop's mitre is called the mitral v fll ye : 

' it prevents the passage of the blood back into the auricle dur- 

ing the contraction of the left ventiiele. 

The aorta, or arterj' given 
off ti'oni the left, ventricle, is 
t]<is(il by ii valve similar to 
tliat Itiund at the mouth of 
tile puimunary artery ; it is 
called the semilunar, or 
fourth valve. 

The tigure represents the 
left side of the heart; 1 h 
the interior of the left auiv 
cle; 2, cavity of the apjwn- 
dix; 3, mouths of right pul- 
monary veins; 4, sums into 
whicli left iiulmonary veins 
open ; a, left pulmonarj' veins ; )), auriculo-ventricular o|iKn- 
ing; 7, coronaiy vein; S, left ventricle; i', cavity of ventricle; 
a, mitral valve; /*, colunmic cania-; r, columnic carnie of in- 
ner surface: 'A an-h of aorta; c, pulmonan,- arter\-;/', ductus 
arteriosus; </, left pulmonary artery ; /(.right ventricle; «, point 
of light appendix. 

In the fi>llowing figure, which represents the heart cut acroes 

Wh«t U the rtinrtion of tho nkiupld «n'l rieht ■■ 
vnlor. ii» tiiinir, niinpi>>liiiin,]iDsllloa ; iW fuiiiih vnlv 
■lid kft Hrmiliinar vulrctF 





SOUNDS PRODUCED p^Suka TIIE IIEARt's ACTION. 81 

it^ l^ase to show the valver, t, f, t is tlie tri- Fiff.so, 

cuspiil valve ; ;«, w, the mitral; c,/jthe sem- 
ilunar valves of the aorta and pulmonary ar- 
tery. 

The two sets of semilunar valves have their 
margins peifectly free, and elose the openings 
into the aorta and pulmonary artery liv their „ , " „ „ _ 

t\ \ • !■«■ ' 1 I V»!»« of th» Ilwct 

contaet. But the e«se is dinei-ent with the 
mitral and tricusjiitl valves; their margins are attached hy 
small tendons to muscles which arise from the walls of the 
ventricles, and which aid in working these valves in a proper 
manner. These nui.«cles and tendons of the valve are lieauti- 
fully shown in the heart c»t' a wheep, as well as the relative 
thickness of the auricles and ventricles, and the muscular bauds 
in the latter. 

During its action the heart emits i>eculiar sounds, which 
are not produced, as was formerly thought, by the contraction 
of its muscular fibres, but are caused by the passage of the 
blood through the valves, and their sudden closure. 

By the character of these sounds we may with ease recog- 
nize the contractions t)f the auricles and ventricles. The au- 
ricles at the base contract at the same moment, as is readily 
proved by vivii^^cti^ns ou animals; the sound pi-oduced is rep- 
resented by the syllubh- hrU,._ Tlils is foll.nved by the con- 
traction of the veil trick's, -whiL-h also iiiDve tni^ctlicr, ;ind jiri»- 
duce a sound repn'si'nted by the syllalite fnp, shorter, <piickcr, 
and shari>er than that produced by the am'icles, 
"XTiie first sound is caused by the passage of the blood through 
the mitral and tricuspid valves, and terminates by tiieir entire 
closure. The second sound is produced by the IiIoikI floH^ng 
through the semilunar valves of the aorta and pulmonary ar- 
tery, and ends with their sudden closure, by the fluid forcing 
the valves back as the ventricles begin to expand, just as the 
valves of a forcing-pump act under similar circumstances. 

In disease of the \'alve8 these sounds are changed, the modi- 
fication being generally due either to the formation of a depos- 
it on the valve, and its consequent thickening and roughenmg, 
thus obstructing the passage of the huid from the auncle into 
the ventricle, or to its failure to close the opening l)et\veen the 

What Tnhes hnro free murKitit? Wlint orEitli nrc nirnrhcd lo ihc miLrnl nnd [ricuFpJil 
vbWm? Whnt U iheir runciiun? Wlmt \a tlic nntiirc of [he umnd iiroduccd liy llic niiri- 
clci — by tliD TcntricIcB? How arc tlicr producei]? How are ihu Mand» modiiied by dii- 
caac ? Tu vrbat MB the modiEcatioiu due ? 

F 



82 TItE PULJIONAKY DLOOD- VESSELS. 

two cavities, permitting the Idood tu pass backwan] thruushl 
the opening into the auricle. "" I 

When these almormal eouttitiuns exist, the character of thel 
Bounils is changed, anti a liiizz or murmur accompanies the lirsti 
long sound or the second sluirt sound. The valvet* are often T 
both rough ami deficient; iu such a Ciise the murmur is heard 
witii Iiotli sounds. 

.Xot only can the experienced physician determine that the 
valves are diaciised.liut he can also state, with almost absolnle 
accuraey, iu which ■wahe the disease exists. This is aecom- 
]>lishe<l in part tiy finding whej-e the munnurs are most in- 
tense, and by noticing other phenomena, such as the pulsation 
of the veiua 



LECTURE XVII. 

HLOOD-VK?8EL8 OF BODY. 

Pulmonary and Systctnic Blondveaseh. — Courtc of the Pulmonary Ti«- 
aeU.~The Aorhr.—Ils TMvieioHs.—Ila Ih-ttiiuatiori.—T/ie Cardiae Ar^ 
(ery. — ^trteria Iiniominiita. — C'lnimott Carvtul. — Sutmlaviau. — Arterut 
o/f/ie Cpfier Ertrnuity. — 7'Af lulenoelul Artfrlts.— 'Dit Phrenic, — C» 
Hue .Ijcw, — Strpi^rwr MfMuUric. — Ot/ier Alnloininal Arterit*. 

From the study nf the heart we pass to the examinatiou of 
the bkxjd-vesKels. They are divided into two classes: 1st. Those 
conneited with the circulation of the blood in the lungs, c-nlletl 
puIinon;iry vessels; and, 2d. Those engaged in the eniiveyance 
iif nntritive material to the various tissues of the hoiiy, to 
which llie name of systemic vessels has been given. 

The pulmonary vessels consist of the pulmonary arterj', 
which takes its origin fi-oni, and i>pens into, the right ventricle; 
it divides almost inimo<liately into tlie risrht and left jmlmona- 
ry arteries." one of which passes to the right, the other to the 
left luuiT, conveying the dark venous blood to tliose oi|!ans to 
lie arterialized. 

The right i)nliiinnary artery entci-s the right lung at its root, 
and divides mnuciliately iuto two bninchesthe upper diHsiou 
giving a brunch to the niidille lobe. The left pulmonar)- artery 
enters the left long, and divides into two branches, wluch con- 
vey the bUhid into the two lobes of which it is com]>os«Hl. 

"Each of the large diviwons of the pulmouarj" artery' cuntinue 

KuN At «aid> of the pnimamaf 



XnE AORTA AND ITS BRANCirES. 60 

to subdivide in tbe tissue of tlie lungs, until they finallv term- 
inate in capillarj' vessels, which are about nuiTf "*" "i" "'^^ i" 
diameter, enabling the discs, which are 45^9 of an inch in di- 
ameter, to pass through them with ease. The capillaries fiinn 
an intricate network on tlie walls of the aii'-cells of which the 
luugs are composed; they then unite and originate larger ves- 
sels, which ha\e llie composition ami stnicture of veins, and ul- 
timately form four ])ulmonary veins, ^vhich pass from the lungs 
to the heart, and enter tbe left auricle at the base of the 
organ. 

The systemic vessels are more difficult of description than 
the pidmonaiy, since they ai'e more numerous and intricate. 

The great ai-tery \vliich receives the blood from the left ven- 
tricle is called the aorta; it is about one inch in diameter, and 
ia curved, ft)rming an arch. Tlie flrat part of the \e-Sftel passes 
upward, and in called the ascending aorta; the second curves 
and passes backward to the left side of the vertebral column: 
it i'i called the aii;h ; while the third portion passes down- 
wai"d, lying partly on the left side and partly on the verteltral 
column: it is called the descending aorta. 

The first i)ait of the descending aorta lies in the thoracic cav- 
ity ; it is cousetpiently known as the thoracic aorta. It then 
passes through an opening in the diaphragm, or muscle which 
separates the two gi-eat cavities of the trunk, into the abdonii- 
nal cavity, where it is called the abdominal aorta. In the Imv 
er part of this cavity it divides into two l>ranches, the right 
ana left iliac arteries, whicli 8U]iply the lower extremiticH with 
blood. 

The branches of the aorta may be studied under the follow- 
ing divisions: 1st. Those of the ascending jiortion; 2d. Those 
of the arch ; 3d. Those of the thoracic ; an(l, 4th, Tliose of the 
abdominal jmrtion. 

The bmuch of tlie ascending aorta is the cardiac nrteiy ; it 
is given off close to the heart, so that its mouth is closed by the 
semilunar valves of the aorta wlien they open to give the blood 
pas-sage into that vessel. 

The branches of the arch an; 1st. The arteria innojninata, 
which is about one and one half to two inches in length; 2d. 
The left common carotid; and, 3d. The left subclavian. On 

Where are ihe pulmonnry cnpillnrioB f Ilow many pulmonary vcini nrc tlicro? Whnl 
blha name of iho Rrtat syatcmie nrlPtyf Wlint is irs dinmoicr? What is its ahnpc? Into 
whsl portions is it ilivided* Whnt nro ibo division" of (lie dpsccndinj; Bonn? Iloiv docn it 
torminnte? Wlint is thp firsl branch of the norm? Whnt am ihc branches of ihc nrth? 
DcMribe ttio artcrin innomimiln. 



TUK CAROTID ARTERIES. 

the i-iglit Hide the common carotid and snhclavian ai-e formed 
by the bifui-cation of the arteria innominata, 

Fi-om their ongin the common carotids and subelavians on 
both »v\es pursue a tfiiiiilar coui-ae. We shall therefore de- 
scribe the couree of the vessels of the right eide. 

j^ ^ The common caintid, a, 

passes oblicjuely iiji the 
neck toward the angle of 
the lo\\er jaw, whei-e it 
reaches a position about op- 
posite the Adam's appl«; it 
divides into two branches, 
the external and internal 
cai-otids. The extenial car- 
otid, A, pusses up <m the out- 
side of the skill], liiving off 
a number of branches, which 
convey blood to the t^calp 
and other tissues of that re- 
gion ; the most important 
of these are the occipital, o^ 
which passes to the b&ck 
of the head; the maxillary and tenijioral, ?/, j/, pas*-ing to the 
temples and the side of the head, Tlie internal carotid, c, 
passes toM'ard the apex of the petrous pai-t of the temporal 
bone, where it entei-a the cranial cavity through a canal in that 
bone. 

In man, the canal which contains the internal carotid is 
eurvai, so that the force of the pulsation of the ventride is 
lessenetl by cnni]>elling the blooii to follow a cun-ed coursa 
In many of the herl)ivoia, in whom the head is kept for a long 
period in a dejiendent pnsition while feeding, the carotid aijlita 
up into a number uf small l>raiiches as it passes into the skiill, 
proibu-iiig (1 siniiliir rcstilt in ii hhhv jHTfWt manner. 

After tiUiriiiL' tlie <-i'.iii!;il cavity the internal carotids unite, 
and fonn a series nf o)iiuiiuiii.!itiiig vessels at the base of the 
brain, called the ci,nl<' of A\'illls, i\-«m which that organ is sup- 
plied with bkw)d. Tlie .ibjcti of tills free eoniraunication of 
the cai'otids from both siiKs is tn jmtduce an equality in prees' 
ure of liliKid on all ]mi-ts of the bniiii, and also a fi^e and equal 
supjily in case either carotiil should be injured. 

iVIim unit! hmnchrs ? l>«crih(i the es- 




GuUnritkB ia <l>o 



lino of iho riimmor 
fuune iinJ hrnni-ln-i 
(HiiwortliUnriorT 



lI,OOD-%'ESSELS OF TIIE fPPEll ESTREMITrES. 87 



ITlie sulx'lavian passes outward to the upper extremity, to 
apply it with IiUxmI. In the middle of its course it lies on the 
ret nb, aud uuder the clavicle ; heuee the uame suliclaviiiu : it 
ives off a uumljer of Viranchew, which supply tlie muscles 
bout the shoulder; one of these, called the mammaiy, passes 
(lowu the front of the thorax, and oommunicates \v\ih an artery 
given off by the external iliae in the ei-oin. 

Reachiui^ the anupit, the subclavian becomes the axillan'' 

until it gaius the inner edge of the biceps muscle, when it is 

called the brachial ; it follows the iuuer edge of the biceps 

down the arm to the elbow, where it liifuiVJttes, sometimes 

" above, but usually below that joiut, iuto the uluar aud radial 

rteries. 

The ulnar ai'tery,as its name indicates, I iea on the ulnar side 

1 its coui'se down the fore-arm, while the radial lies on the ra- 

ninl. A third artery, called tlie interosseous, a bi'anch of the 

bltiar artery, also passes down the fore-arm, lying between the 

■wo bones and on the interosseous ligament. 

From the wrist the radial passes around tlie metacarpal bone 
bf the thumb into the palm of the hand; uniting with a branch 
f the ulnar, it forms the deep palmar arcii,from which branclies 
i given to the fingers, called tlie digital arteries, which I'un 
ilong the outer and inner border of each finger. In like man- 
lier tlie ulnar terminates in a superficial palmar arch. 

Owing to the free coinuiunicatiou of the ulnar and radial 
rteries m the palm of tlie hand, wounds of either of these ves- 
iels, or of the palmar arch, are apt to cause a considerable loss 
f blood ; and it is necessary always to tie both ends of the cut 
irtery, or, if there is difficulty in finding them, to tie the brach- 
ial Iiigh up in the arm. 

In wonuds of other arteries it is sufficient to tie the end on 

^ the artery nearest to the heart, as there is but very little chancel 

of a flow of blood from the other extremity; but in the easel 

of the ulnar and radial, the free communication throiigti the! 

palmar arches renders the precaution of tying both ends abso-/ 

\' necessary. 

The branches of the thoracic aorta are the intercostals, one 

I each rib. They run in a groove on the under and inner 

3 of the rib, so that they are protected from violence, and 

at is ihe connie of ilic •iibiJiivmii ? Wlmt nre its brnrn^lnw? Wi>«rij does ii Wnme 

hdlUry? Itesciibe llie Imidiial. WliiiL utv ilia (elmmnl brunclics <>f llie bruchml? Ue- 

' "le llie ulnHT, nuliiil, interoHsefiiis iirtcrie*. Ilou* ix llie ilu^p ]iiiltnnr iircli fiirmeJ ? Wliere 

? Wiiiit nre iis bninclies ? Wlmi is llie peculinritv of wuiiiiiIk of the ni'teiies of the fore- 

nif Wliaiara ibe brunclics of the iboracic aorta? ' Uow ara tbejr pralscted ? 



88 BHAiXHES OF THE ABDOMINAL AORTA. 

can only be wounded l)y a knife, the edee of which is turned 
upward, aud the blow struck so that the point of the knife 
passes upward, and not downward, as is usually the case when 
a person is stabl)ed in this rtgiou. 

The first branch given off by the abdominal aorta is the 
phrenic. It takes its origin from the great aiterial trunk, just 
as it is passing through the i:lia])hragm, aud, entciing the tissue 
of that muscle, supplies it with blood, 

Tlie second bi-anch of the aorta is called the cieliac axis. 



is not more than half i 



ich in length, and divides into the 
gastric, splenic, and hejiatic, ejich 
of which snjiplies tne organ whose 
name it beaifi. The splenic and 
hepatic, in adilition to sujiplying 
the s]ileen and liver, also give olf 
branches to the stomach and pan- 
creas. 

The third great branch of the 
aorta is the superior mesenteric 
■ It conveys blood to all the small 
intestines, and to the large intes 
tine, with ihe e.\'ception of the d< 
scending colon, sigmoid fle.\'ure, 
anil recti 

Tlie remaining branches of the 
aorta are the renals, of whidi 
thei-e are two, one on each side 
they pass to the kidneys; the in- 
ferior mesenteric, whicL passea to 
those parts of the lai^** intestine not supplied bv the superior 
mesenteric; the spermatic and the lumbar branches, which are 
analogous to the intcivostaU of the thoracic cavity: they run 
aroumi the abdominal walls, and supply the muscles which 
font) them. 

Wh« it tbo fina bninrh nf iI>p iiWi-niiiiiil rn-im f Wlwrr » it pmi off? Vfhn 

SBffW? IVcriihe ibe (^rlic nxi» Wlmi nrv in Imiichesr What Jo ihcr »ili^j f WbM 
it tbo tbinlbniiKhT WlutI (he* il tuj^djrt Wb«t arc tbc rcnutiniuebnuichcs? WbMdA' 




BLOOD-VESSELS OF THE LOWEB EXTKEMITY. 



LECTURE XVni. 

BLOOD-VESSELS OF EXTREMITIES. 

Fi Jllac Arteries. — Internal Jliacii. — External Iliaca. — ArteHet of 
■ ths Zoteer Extremities. — Veins of the Head. — (if the Upper Exlremity, 
I — IJie great Veins of the C/iest. — Veins of the Loiter J£xtremi(ies. — Por- 
tal Vem.—'Hie Course oftlte Blood. 

We liave already seen that tlie aorta teninnates lielow in 
the common iliac arteries, which paas to the I'ight and left low- 
er extremities. The branches of both of the common iliaca are 
the same on each aide; we shall therefore only dcscnl)e those 
of the light side. 

The right comtnon iliac passes to the biim of the pelvic cav- 
ity. It is alKHit thi-ee inches in lenjrth, and divides into the in- 
ternal and external iliac arteries; the funner passes downwai'd 
into tlie cavity of tlie pelvis, and suj)plies the organs it cou- 
tain>i with Iilmnl. Some of its branches pass out through open- 
ings in the walls of the cavity, and supply the muscles about 
the buttocks and lii))s: its terminal branch, the pubic, passes 
outside of the pelvis. 

The e.\temal iliac lies on the brim of the pelvis, and passes 
out iif the abdominal cavity tu the thigh. As it lies on the 
pubic bone, it gives oft'twi' branches, one of which is called the 
epigastric, which passes up the aiitfijur wall of the abdominal 
cavity, and coiiuniinicates with the mammary, a branch of the 
sulichivimi. So that when the external iliac is tied, blood can 
reach the lower extremity tln-ough this circuitous channel. 

Reaching the thigh, the external iliac liccunu-s the fcmin-al, 
which gives oti" in its upper part a largr braiicli callei! the pro- 
funda, that passes backward, and siijjjilics tlic muscles on the 
back of tlie thigh with blood. In the upper third of the thigh j 
the femoral is siipei-tirial, and all necessary operations iwv usa-J 
ally peifonuetl oii it in this part. In the middle third 
deeper, ami gradually passes to the back part of the thigh. In 
the lower thini of the thigh the femoral becomes the jiopliteal 

Wlmt oretl'c iliviHioiM of t lie ilinr nrterics? WhnC i'i the P□u^^=o of tlia intcrnn 
Wlint .lomi it Biijiiilv f Wl.1.1 is llic course ..f rho exrcnml iliar ? Wlint nre tht divi* 
ihc fomoinl artery? With wliat srtery doca iho ciiigaairif eolnmunkinc? In ivha' 
JocB the fL'tnamt icrmiiinlc 7 



yU TIIK VEINS. 

arterj", which lies on the smooth surface of the posterior lower 
part of the femur. Opj>osite the head of the tiliia thn poplite- 
al divides into the anterior and jxisterior tihial.the first pa» 
ing down the leg in front of. and the st-eoinl h^hind the inter 
osseous ligament. In the foot, the aitericp: of the leg form the 

iiiantar ari-h, similar to the j>alniai*, which gives off digital 
(I'anches to the toes. 

The veins iiminieiice in the capillaries in which the arteries 
terminate. In the braiu the venous lilood flows into laro;e car- 
ities formed hythememhranesof that organ, and called sinofcs; 
fivm these it is finallv i-onveved tu the internal jugular veins, 
and carried liy them dfiwn the neck to the shoiUder. and deliv- 
ered into the venie innominntje. The Vilood from the oiitidd? 
of the head is brought to the same [toint hv the external jiigu- 
iar vein. 

Tlie veins of the upper extremity ei>mmeuce in the digitals 
which form the deep ulnar and radial. These UDite at the 
ellx>w,and, receiving some of the sui>ei-ficiai vessels of the fiHf- 
arm,iV>rm the brachial, which, j>as.«iug up the arm to the arm- 
pit, becomes axillar)', then suK-lavian, and finally unites with 
the internal jugular to tV>rm the vena innoniinata. 

The ni^ht and left vena innomiiiata, uniting, form the vena 
- cava desci-ndens which conveys the blootl to the right auricl**. 

Ill the lower extremities the veins of the foot form the tihi- 
als» which, uniting at the Iwick of the knee-joint, lieconie iK>p 
liteal, au<l then femoral, external iliac, ettminon iliac, and Dual- 
ly vena cava a*icendens. which empties the venous blood into 
tW right auricle. 

In addition to the veins we have mentionetl. there are great 
inuuWrs of suuill superficial vessels, but they all enipt^' wKmer 
ior later into ime of tiie large veins of the extn*niities ttr trunb. 
In the upjwr exttvinity there is a superficial vein, called the 
i-epbalie, which itasses up the arm, ctiuveying bUwid ficm KHue 
of the stiperficial ve-sstds of the ft>re-ann to the sulx-lavian. In 
the lower extn-mity ther*^ is a sinitlar vrtsel. which i-onunences 
at the lai^ toK\ and is calli*d the saphenous vein: it carries 
liliM^ ft\»m the suivrfieial veswls «»f the lower extremity to the 
tipper part of the teuHtnil. int«> which it enters. 

In the abdomiual cavitv the reiials are the (4ilv veins of the 



H«lltt>*iw«rilttt»Ml-«rih*>attr*rxti*«>iiTf W>i>t rrwn K«« tW >»■ iHMMnlMM— 
the aiM nrai 4nn«J«Bt* Numf ih* \<(4m of ibr Unrmnmi'i. WWiniMbmihi 
fHM cwn HCrtdkw f Dntrifae the wf^tacU rtta. Dcvcfftc iW Kdnofihe^ioHlMl 




^^*K«i 



TllE UISCOVEUY ItF HARVEY. 91 

large organs, except the hepatic, that empty directly into the 
sella cava &'»ceiKleiis. 

The veins from all the other viscera, viz., the stomach, spleen, 
pancreas, large anfl small intestines, unite together to tVmn a 
short trunk of large diameter, called the portal, which enters 
the liviT and there snbdivides, causing the Idood fnun the ea- 
])illarie-i ni' all tlie a'xlominal organs except tlie kidneys to pass 
thniiigh a second system of capillaries in the liver; tiiese, coa- 
lescing, form the hepatic, or vein of the liver, wliicli cnijtties the 
blood into the vena cava ascendens. The portal circulation of 
tlie liver is copied to a certain extent in the kidney, lint Me 
shall defer the descrijition of the renal circulation until we 
take up the study of the kidneys. 

From the anatomy of the circulatory Rystero, we pass to the 
exatiunation of the course the Idootl follows in its passage 
through the different parts of that apparatna 

The great discovery of the coui'se of the circulation of the 
blood w.is made about two hundred years ago by Harvey, He 
founded his doctrine on the tact that the valves of the veins 
will i)uly allow the fluid contained in those vessels to flow in 
one direction, viz., toward the heart; and the valves in the 
heart also impress upon the blood a definite movement, from 
the ri^ht auricle through the tricuspid to the right ventricle; 
then through the seniilunar valves and jndmonarj' ai-tery to 
the lungs; back by the pulmonary veins to the left auncle and 
ventricle; then through the aorta to the systemic capillaries, 
and back by the systemic veins to the heart, thus tbnning a 
tigure S, the meeting of the two circles being in the heart. . 

The iUscovcry of Harvey was a grand step in the advance-) 
nicnt of physiology and medicine, but it supposed that these? 
iiiovemitnts were all caused l)y the contraction of the heart. f 

Experiments have shown tliat, under certain conditions, the 
force exerted by the heart is not snflicient to drive the blood 
through the capillary vessels. It is, moreover, very difiicnlt to 
make perfect injections of all the capillaries of a given part 
witluHit causing many of them to be ruptured. The most 
subtle injections, and the utmost care in forcing the fluid, gen- 
erally fails to fill many of these niinute vessels, 
" In the explannti<m of the portal circulation of the liver, Har- 



is ihe porliil TEin ? Wliai is tho porml circnUiion ? What \ri\s Iho iincietit itlen 
inling the Hrteriee? Wlini is ilia iruc course of tlie circulnlion? Who wns ihe diicur. 
;i-er? (In wlint facts did llnivey found bin doctrine? Is the Tores exerted by ihelieiirt gi-eot 
idoueIi tu drive tlie Lluud ilii'ougli the copilUries into the reiiu ? 



93 DRAPERS THEORY OF THE CIBCUI.ATIOX. 

vey's doctrine is altogether uusatisfiictory ; and if we consider 
the cases of monstevs born witlioiit hearts, we find that though 
Harvey has taught us the course thfongh which the blood 
flows, he does not satisfactorily explaiu the causes of its move- 
ment. 



LECTURE XIX. 

CIKCULATION OF THE BLOOD. 



Harvey's and Dnqier's Theories. — Affinihj of lAqitidi for Tul>eit. — ^inci. 
pU of Veiituri. — Vauies of the Girenlation m Si/atemic and I^ulmonary 
VtatiU differ. — I^rfeetion of I>raper''s Theory. — Course of variout Af 
ticUs to differeta Parts of the Body. 

Since the day of Harvey, vanoiis attempts have been made 
to oveicj^nie the difficulties against which las siniple tbe<irv 
of the circulation had to contend, and of which brief nienlioH 
has been made towards the close of the last lectiiif. 

By some, these difficulties are met by considering, in add"i- 
tion to the movements of the heart, those of the elastic coat* 
of the large and small blood-vessels under the influence of 
nerve stimulation, and also the respiratoi-y action of the thor«x, 
and the movements of the muscles of the body and extremi- 
ties. All these taken together oflfer, in their estimation, a suf- 
ficient explanation of the causes of the circulation of blood in 
man. 

In discussing this phenomenon, Professor John W. Draper 
admits the action of all the forces nientinned, and, in addition, 
directs special attention to the chemical relations existing Iw- 
tween the blood and the tissues which it is traversing. These 
variations in chemism, and consequent variations in the attrac- 
tion between the blood and the walla of the capillaries, become, 
in his estimatioTi, important factoi-s in the explanation of the 
circulation. The argument is based upon the following con- 
ditions found in the human body: 
/ 1st The heart does not exert sufficient force to drive tho 
/blood thixmgh the capillaries and veins; 2d. The portal cil-cu- 
/ lation in the liver, ana a similar one in tlie kidney, ai-e carried 
1 on without a iieart ; 3d. The existence of acardiac monsters 
\ shows that the blooil can circulate independently of a heart. 
^ In plants the circulation takes place against far greater pi-es* 



Wbera docs Darrajr'a doctriM bit f What b Drapw*! Uwoc; of the cimiluioBr 




TIIE ACTION OF THE UEART. 



•».. 



UolioB in ■ CaplUiTj Tube. 



sure tljan in animals. No heart is employed. Capillniv at - 
traction , osmosis , and cj^^uu^y^ answer all tbe refjuirenients; 
why, therefore, may not these be leading causes of the move- 
ment of the blood ill animals, as well as of sap in plants? 

In order to ex])lain in a satisfactoiy manner the movement 
of the blood in the vessels containing it, we nmst first devote a 
bnef ajjace to the examination of certain physical phenomena 
upon which the circulation depentls. 

If there are two liquids in the tube a v, and the liquid a has 
a stixtng affinity tor its walls, but loses ^^ ^ 

it as Hoon as it reaches the point c, it ^ ■—" " 

is evident that there will be a flow 
from a through c to v, and the move- 
ment will continue until a is ex- 
hausted. 

The principle of Ventviri also 1 
its influence m producing the cii-cu- 
lation. If a current of fluid Ls flow- 
ing throuah the tube a b, and a 
smaller tui>e, e d, empties into it, a 
movement from the smaller into the 
lar-jcv tube will be established. 

A|)])lying these and itther phys- 
ical plieuomeua, of which we have 
spoken, to the explanation of the 
systemic eiivulatiou, \ve find that it 
is the function of the heart to keeji 
the arteries liUed With blncid, that tliere may always be a free 
gupply of fluid delivered to the ciijiillaries. As it enters the 
capillary ves.se Is the lilood is arterial, the discs being laden with 
bxygen. The tissues through which the capillaries pass are 
Tomposed of carbon, which, at certain times and in certain allo- 
^pic conditions, has an intense affinity for oxygen. The discs 
cntaining the oxygen conseijuently move forward to deliver 
\ to the atoms of civibon which attract theuL 

As soon as the oxygen has been surrendered to the carbon, 
md carbonic acid formed, the blooil no loiigir has any affinity 
pr the walls of the ca])illar}' tubes, and t!ie conditions that 
^en exist are similar to those atibrded in the case of the exper- 
ment with the liquids a v, and the tube c. 

As fast, therefbi-e, as the artennl blood Ijecomes venous, and 



liquid hn< nn iHiiiliy (m I 
Whftt ia ihp principle of Vcutnr 
[he caiiillarici 7 



Wlini k tile duly of Hir lieart ? Win 



SP)Jim\^'?S>\'V^ 



94 



CIROl'LATIOS IH" XnE CAPILLARIE-i. 



loses its affinity for tie walls iif tlie capillaries, it is pressetl fal 
ward into the veins l.y tbc fivsh portiuiis of m-tfnal Itl, 
wliiclj move up to nnitc witli tin- cailnm of the tissnesi. If tW 
view of the oaiisst- nf t!ic ciiiulntiuii i.s correct, it followft tla 
the passage of the hlood thnniij:h tiie smallest caiiillarifs nhoiJ 
be continuous, and free from the pulsation that exists in 1 
arteries. 

Examining the tirculation in a li-og's foot under the mia 
scope with a jxiwer of about 200, we find that not onlv dui 
tlie condition of continuous motion sjjoktn nf exist, but tioi 
time to time the blood moves backward toward the arterie 




a movement which, of course, it is perfectly impossible for t 
heart to produce, but which is readily explained by the lo 
of atliiiity of certain atoms of carbon, and increased affinity 
others', attracting the blood more powerfully, and divertiug 
fi-oni its previous course. 

The supply of venous blood to the veins by the capillari 
is therefore continuous and mthout intennission, and the flo 
of the fluid in tliese vessels is free from all judi^atile churacte 
According to the doctrine of Harvey, the right auricle esei 

Wlinl fiicw rorroljornlc Drfipvp'* [lii-orr? How dom the blond more in Uie »a|ii 
What U the oMnrcof ihc mnTfmeiii in iho veins? What wm Harrcy's iilcMi ngm 
tDnedon of llio right nuricic? 



TilK TIlEOItlES OF IIARVKY AND DRAPER CONTRASTED. 5)5 

au exhausting action on the venous blootl ; but, if we reflect 
for a moment on tbe yielding iiatui'e of the walls of the veins, 
we see that any sneh exhausting process is impossible. 

The ])resence of valves m the veins, on the existenoe of wliieli 
Ilarvey founded his doctrine of the oireulation, does not in any 
way eontriidii.-t or iiitei-fere with the theory of Draper, for then- 
fniii'tion is -still the same; and, since they are found altogether 
in the extremities, whei-e the veins are sultjected to great press- 
ure dunnj;tlie vi.ili'ut eontractlons of the sun'ounding muscles, 
they are alisnlutely neeess;ivy in order to prevent the refnu-gj- 
tatio!! lit' the liiooil liaek upon tlie capillaries. 

In the pulmonary cireulation, the conditions wliirli |irndin-e 
the movement of the blood are exactly tlic oji|»i-.itc •■{' tliuse 
which cause the systemic circulation. Tlie Mmid delivered to 
the pidnKHiary caifillaries is laden Avith earbonic aeid ; the air- 
cells, (in tlie wall^ of which tliese ea|ii!laneH are distributed, ai-e 
tilled with ().\ygen gas, whierh eiidnsmnses through the walls of 
the vessels, and, interchanging with the carbouic acid of the 
blood, arterial izes it. 

As fast as the \enou9 blood sun-enders its carbonic acid in 
the pulmonary capillaries, it also loses its affinity for their 
w^alls, and is conseipiently forced out into the pulmonai'y veins 
by new portions of venous blood, \vhicli pi-ess forward in the 
cajiillaries to exchange their carbonic acid for oxygen. The 
nictlind of operation in the lungs is similar to that m the sys- 
tende vessels, but the conditions are difl'erent— not only as re- 
gards the causes of the circulation, but also as regards the con- 
tents of the great l)lo(«l-vesaels ; the arteries of the lungs con- 
taining venous, and the veins arterial blood, while the system- 
ic arteries contain arterial, and the veins venous blood. 

The great advantages of Drajier's theory have gradually been 
recognized. The fact that it atibrds a clear, intelligible ex- 
jdanatinn of the portal circulation in the liver and kidney, and 
accounts for the circulation in acardiac monstei-s and such ex- 
c^'ptional cases, gives it a force and power in which the doc- 
trine of Ha^^•ey is very deficient. At the present time, there- 
fore, Harvey is acknowledged as the discoverer of the course of 
the circulation, but to Draper is awnnled tlie discovery of the 
leading cause of the circulation of the blood in tbe capillaries. 

We have now described the divisions of food, and the fnnc- 

Whnl is ihe functinn of tlio vbIvcb of tliu vcina ? How di> liie cniiwa vrliich iirotiucc cireii- 
Intion in ilio Enpillnrics diffi'f in llic iinliniirmry nnrt evsiemip vr™'ls? U tUc Wnoil in tlie 
piilmonnry tTKty nrwriiil or vengns ? Wlmi iiuculi urines of circnlaiion dots Drnjier's llioury 
cx]>laio thftt Harvey's docirinc can nal? 



90 STAGES OF INTRODUCTION OF FOOD INTO THE STSTEM. 

tioiis of digestion, absoi-ption, ami circulation, which are en- 
ga<jeil in prepaiing and delivering nutnnitnt to the different 
tissues of tlie body ; wa are therefore pi-epared to pass to the 
cxaniination of the oi^'ans of secretion and excretion. Before 
Ave tiilii' up the consideration of this division of oiir subject, wu 
slinll devnif a short ppace to a synoptic review of the functioua 
already t^tiidJed. I luive found such tables to be of great value 
to stiidfiits, enabling them to fix the steps of the introduction 
of iiutiinieut into tlie tisf^ues more lirnily in their minds, and 
to attain a connected idea of the various functJone, and their 
relations to each other, 

The manner in which the following tables are constructed 
eualileu tlie student to select any article of food, and trace it 
step by step to some organ or tissue. Many may oliject to 
this system, ui^ng that the substance under ijuestion does not 
retain its qualities thivugh all the processes to ivhich it is suli 
jwted, nnil therefore any such method is useless. I ivould an- 
HWer that it is not intended to assert that ai-tich's of food re- 
tain their character during the various operations of digestiott 
and absoii)tion; but an the expeneiite of a number oV years 
hiiH ttiiiglit tne that this tabular an-angement is of gi-eat value 
to students, it is intro<luced here for tlieir advantage and con- 
Vfiiicnce. 

In uialving use of the synoptic table, any special article of 
food, as, for e.\ainple, fat, may be traced to any part of the sys- 
tem. It passes tiiit)Ugh tlie vanmia divisioua of tlie dtgestiva 
and absorplivt^ apparatus until it reaches the large lacteal 
trunks, \\ luTe ()ne jH'rtion entei-s the blood by the mesenteric 
veins and \ fiia ni\ a aseendeiis, while the other part reaches it 
by till' reiepljteulnm eliyli and vena cava deseendens. In the 
heart the two divisions aiv reunited; sent to the huigs to re- 
ceive o.\ygeii ; then cmiveyed tc) the aorta, from wliich 
course to the hi'ad,u|)per or lower extivniitiesjor great alidom- 
inal organs, nuiy be tiined to its i-etnm to tlie right auricle. 

Itv slnd\iiii.' lliis talile in eoinieetion with a tew^ example! 
of diilereiit iiitiiles of food, the student will soon become peP; 
fectly laniitiiir m ith all^ the leading facts in digestion, absoip 
tion, and circulation; for, with the passage of an article fixim 
jxiint to jHiint, he so«m conneeta the changes width it undei>' 

Truce tliocnnrw'i 
MiliLVtnn inift n-t 

dm iii.Utlinii.1— lll-r ^ 

kiiliiO'L Tincc iliv IiIimn) frnm the fi 
[lio briiin to ills kidni'.vi— (Vi: 







o 
o 



p 

Q 
O 

H 

o 

O 
<: 





^ J 5 >. g g:* ^ S H 



bO 






rail 1^ 



>^ 



= "ij 



O :3 B 



e 



s 



t 



i 



•5 = ^2 






/ 



G 



N 



'A 

< 

o 

ft 
<: 

m 
U 






o 

<: 

c 



c 
ft 

c 
c 



Pd 



o 






OS 



a 



.5 « 






O XL 



O 

E 

E 
o 

O 



^ 



E-H. 



o 












c 



CO 

c 
e: 






. ?« c c« —^ 

— C s — .5 

e: M es *S 
o j^ 'd CI 




6S 

fit 



ACTION" OF SPITEROIDAL CELLS. 



99 



LECTURE XX. 

SECRETION AND EXcnETION. 



goes at each step, and they all become associated together in 
his Tiicmorj'. 

Having completed the examination of the nutritive process- 
es, we next pass to the study of the mechanisms by which the 
etfete niatenals that have arisen duiing tlie action of the vari- 
ous tissues of the body are removed fi"om tlie system ; wn 
therefore commence the consideration of the organs of secretion 
^jflnd excretion. 

^^Krmation of Secretion*. — Structure of GUmds. — Action of Spheroidal 
^^B Celin. — Filtration. — 77le Mammary Ghind. — Its Chanyta and IHseaaex. 
^^^■^ Colostrum. — Oryana of Excretion. — The Skin. — Vomposition and 
^H function of the Skin. — Itt Appendages. — lie Glands. — Their Functions. 

Secretion and excretion are accomplished by means of 
glands , which are all constructed on the same principle. The 
simpIeHt form of gland is a tube, lined on the interior with a 
species of mucous membrane, composed either in part or whol- 
ly of spheroidal epithelium ; the membrane is freely sujiplied 
with lAootl l)y an extensive and intricate system of blood-ves- 
sela. 

Spheroidal cells are always employed when the gland is in- 
tended to produce a secretion containing extractive: they act 
by absorbuig and removing fi-om the IikxkI substances which 
would, by accumulathig in the system, become deleterious and 
jiroduce disease. After the cell has reached its adult size, its 
walls either deliquesce or burst, and surrender theu' conteutB 
to aid in producing the secretion. The substances formed by 
cell action are usually verj' rich in carbon and hydrogen, being 
often fatty in their nature. 

With tlie exception of the extractive, the other constituents 
L secretion pre-exist in the blood, and are separated by filtra- 
lon from the capillary j)lexus on the walls of tlie tube. 
I The glands which iii.iy be with pi-opriety classified as se- 

leting are those connected witli digestion, i\liicli lune already 

sen described, together with the i}3-opei-ties and functions of 

Id fonncd 1 Describe ilio simplpst foiiii of kIihJ- Whnl a ihp pcciilinr 
1 of Hplwroiilnl cells? WliHt is the chnrncli^r of tlic bodies nepgralcd by cell nction? 
« the remaining conslitncnn of Ihc secretion scpnratcd? Wberc ore the secreting 
lifband? 




100 



THE COSIPOSmOS OF THE SKIN. 




tlii?ii- secretions. To these we may add the manimarj', lacbiy- 
nial.aiid nome otlier small glands which have special functiow 
in connection with certain organs, which will be described 
iH'reiiftei'. 

Thi! mamniiii'y gland is conatnieted on the same plan as tlie 
Hulivary glands, being composed of a number of lobules, the 
ducts of which converge toward the nipple. It 
ia peculiarly liable to cancer, the deposit tak- 
ing place with greater frequency in the bivasts 
than in any other organ. 

The fii"at portions of juilk secreted contain a 
great numl»er of large cells, called colostrum cur- 
jiuscles. They impart a purgative property to 
tlie milk. 

They are i-epi'esented by the lai-ge circular 

bodies in the adjoining figure, which also gives 

rirM»nim.rr H very good idea of the appearance of milk when 

"^■'' seen through the microscope, under a moderate 

t\f.m. magnifying power. The small objects are 

till! ordinary milk globules, which vary 

from j^ to rrhrj! "* *i^ '"^h in diameter. 

Tlu-y consist of a fatty, or oily, substance, 

incloseil in a pellicle of casein. After a 

timi', these globules rise to the sni-face and 

form cream. 

Tiiu urgans of excretion are the skin, 
lungs, and kidneys, to wliich we may add 
the spleen, livcr,and some small glauils con- 
nected with special functions. 

The xkin consists of two distinct layers. The external, com- 
niwwl of pavement cpitiielimn, is <,\)ntinnally reproduced as it 
19 woru away liy contact with rough sultstiuices, and is called 
the cuticle. The internal layer is called the cutis vera; from 
it the cuticle originates. The skin is very freuly supplied with 
blood : ilL,<^"t{ m t, i i two sets of glands , one of which removes 
Mater, Baltft, ahd Viluble sutiHtniuvs, while the other secrelts 
oily bmlipjt. Many npiH-ndages, as hair, nails, and horns, are 
uttMched to the dkin, and ai-e describe*! with it. 

Tile viijtliiy of (he integument is si» great that it may with- 
out dltlicuhy lie transplanted fnnu out- platv to another, as is 




OiliMlnl L'ofvuklua u( 



l^noribs ihv tQMnmitrv Bl*n<l- Wh«i JUom* b ommni 
rtoo. WW>i«l>i«l«>«niif ih«»kinf WImI w 



n ItiB eland ■ Whal an «• 



TRANSPLANTATION OP TISSUES. 




I 

I 



frequently done iiy surgeons in 
tlie pfi-forniance of sucli Taliaco- 
tian operations as tlie furmatioii 
of a new and iiertec-t nose to 
take the place of that member 
wlien it is destroyeii }>y disease. 

In Fig. 89, a is a representa- 
tion of a specimen in the Hun- 
terian Museum, in which a hu- 
man tooth was transplanted into 
the comb of a hen, and in the conrsc of 
a few days became attached and grew. 
In A, a cock's spur was transplanted to 
the comb of a hen, wliere it grew rapid- 
ly, owinff to the superabundant nutri- 
tion of the part. In the third sitecimcii, 
"<•, in w*hich the spur was Bucces>st'ully 
transplanted to the comb of a cock, it 
grew with still greater I'apidity, and as- 
sumed a spiral form. In these interest- 
ing experiments we can not l>ut admire 
the ingenuity of Hunter in selecting 
the cock's comb as the tissue 
with which to experiment, for 
itrt highly arterial character 
'fttforded greater opportunity 
of success than any other tis- 
sue that could have been cbo- 

n. 

The epidermis, or external 
skin, is merely for the purpose 
of protection ; and we find 
that in those parts which are 
subjected to continued press- 
ure it becomes thickened, so as to fulfill the purpose for which 
it is employed. 

An excellent illustration of this fact is affoi-ded in fevers. 
[■Tvlien the patient has been confined to his bed Ibr a consitlera- 
ble period, and the epidermis is cast off from the soles of the 
feet, leaving them covered with a skin a.s delicate as that «-'f a 
new-born cliild, and so sensitive that the first attempts to stand 
or walk during convalescence are productive of severe pain. 

Dcsvribu tKo cpiilenau. Wba( ilcierminM iia Lliii:ktieBi ? 




APPENDAGES OF TlIE fiKLN. 




A very good illustration of the tliicV 
emng of the skin fn>in pressure is tlie 
liird calltms, called a corn, which is usu- 
ilh formed i»n tlie upper surface of llio 
t es but which in sometiiuei^ produced 
Itetueeii theiii. The latter variety is ex- 
ceedingly painful. 

The layer of epidermis in contact with 
the cutis vera is composed in part of 
telli, which contain a cousideiahle 
amount uf coloring matter in the dark 
lateK Wlien this is removed the cutis 
\ eia pi-esentH a pink appearance, duo to 
tilt great numlier of capillaries it con- 

E1.U .1 l'"1..i mn-a\A-6 ill Di.nielci. taiUS, 

Tlie nails are protlneed fix)m the cut- 
icle, ami are horny gi-owths which originate in a fold of that 
membiane. The rate of increase varies 
with the perfection of nutrition, and it is 
said that the tlniiiib nail can be repro- 
duced iu four iiiuntlis, but the time ^eeins 
to lie overestimated. 

The hair follicles also originate in a fold 
ot epiderniis, which assumes a tube-like 
fiiini and produces a depression in the 
denna. Each hair takes its origin from 
the bottom of its own follicle, and may be 
considered as being composed of two partB, 
an mternal or medullary portion, with an 
external epithelial eo\eiing, fbmied of 

f)a\ ement cells, which overlap each other 
ike tlie wales of a fi.-^h. It is this pecol- 
iant\ which enables us to cut a single 
hau witii a sharp knife when it is held Dy 
MOV ui.ira HI one extremity, the edge of the instrumoit 
passing with comparative ease between tlie exposed scale-like 
margins of the cells when applied in that manner, but gliding 
over them, and failing to cut the hair, when it is held ny the 
other extremity. 

The ducts of the glands of the skin pass through the cuticle 
hut do not appertain to it. The papillat also, though they pro 




THE GI.AXD3 OF TDE SKIN. 



103 



of fibrous 




ject into the cuticle or epiJeiiuis, can not be regarded as be- 
longiug specially to it. 

Tlie cutis vera, tnie skin, or derma, is i 
tissue, ■\vliicli connects it with the under- 
iying tissues, and holds in position the 
blood-vessels, glands, uer\'es, involunUiiy 
muscle cella, and the other parts wliicli 
aid in its aiiistruction. 

In Fig. 92, a is the derma ; h, rete niu- 
eosum ; c, epidermis ; d, sudoriparntis 
glands ; e, their ducts ; f, their apertures ; 
f/, hair sacs; /*, sebaceous glands; ■/, depos- 
its of tat. 

The sebaeeouH or ceruniinous yknds 
are found in the skin of all parts of the 
lM:idy, and usually in connection with the se«ionut-kinm.6nin.-!io 
hair t(>Ilicles. It is their office to lubri- 
cate the skin," and keep it soft, and flexil>le; they also furnish 
the hair mtli the oily material necessary to give it 
a glossy look and keep it soft. The seci-etitm of 
these glands is almost entirely the product of cell 
action, 

The sudonnarous glands are composed of a tube, 
which, commencing in tbe skin, passes to the low- 
est stmtnm of the derma, or even to the tissues 
beueatli, where it forms a coil, among the meshes 
of wliieh blood capillaries pass in every direction. 
The coil and its cajtillnriesfonn a small gland, the 
tubular jxn-tiou of which is lined with pavement 
epithelium thronghout its whole course. 

The secretion of the sudoriparous glands is com- 
posed entirely of water and f»alts, and substances 
soluble in water; it in free from the extractive 
which exists in the secretion of other glands, and 
atfbrds an interesting confirmation of the fact that 
spheroidal cells proiluce that constituent, the su- 
doripaj'ous fluid lacking the extractive or fatty 
bodies, because the gland does not contain the peculiar cells I 
Avhich are necessaiy for the sepamtion of such substances fi-ora 
the blood. 




Dc'cribo tho cuii» vem, Whnt is iliu rtinclioii of iho Bobttccous glimilB, nml ivlicre nre 
\k\ foiinil ? Describe llio mdoripiir'iiiB glanilfi, llicir poBilioii and fimcliou. Huw do ihey 
Ml What U ibu const mclion of ihc sudoriparous diiid? 



104 ACTION OF THE OLANUS OF TIIE SKUJ. 

Tlie study of the glandular system of the skin presents some 
points of coiisiderahle interest ; among these, the separation of 
the mere filtering mechanism, represented hy the sudoriparous 
glands, fi-oni the projier secreting spheroidal cell of the eeW 
ceoua glands, is perha])s the most interesting, since it gives us 
the dew to the explanation of the at^'tion of the kidney and oth- 
er organs. In addition to the formation of excretion, tlie glands 
of the skin also absorb many substances with which they come 
in contact. 



LECTURE XXI. 

THE KESPntATORY APPAEATCS. 



IMvUion* of the Jieapiratitiy Apjiartitiis. — The I^iryjix. — T/te TraeAea, — 
7'Ae Jlroiiehi. — Thr Air-cfil«. — The Lungs. — The DicUions and Mem- 
bnities of the Lungg. 

I u.KTE shown by careful experiments that nearly one half 
of the insensible lo.ss to which the system is subject occurs 
thi-ough the channel of the lungs ; we tberefoie pass to 
the consideration of the structure and fnnetions of the res- 
piratory apparatus, which consists of the larynx, trachea, bron- 
chi, aud capillary bronchi, which, with the air-cells, Ibrra tlie 
lungs. 

The ]ar\-nx is a pyramida]- 
shajied liox, tV»rraed of cartilage, 
linetl with inuooiis membrane. It 
I i-ontains the oi^nism by which 
I the voit-e is pn^luced, anil lies in 
Intiit of the i>hamyx, so that the 
fiMxl jwiases over the top «f the 
larviix to rvach the phamyx, or 
entrance to the digestive aptwra- 
tns. In onler to prevent water 
and !*>lid fixxl entering the lax- 
ynx.it is fumishetl with a valve, 
I, (.■allrti the epiglotti*. whieh ehwt«j! the entrance to the air-pfts- 
sufps durint; deglutition. 

^TlKt triK^i* |uu«)t<s I'nuu Uiv knux to the canrv- of the 
At9*. Il consMts vS% nuntber of rings of cartilage, which are 




anri 



llnnite ita knnx. Whal btH 



r 



CAPILLARY BRONCHI AND AIK-CELL9. 



105 




conneeteil by membrane, forming a tube with stiff walls, wbicb 
can resist the pressure of tlie muscles of the neck, and prevent 
the closure of the airpassaaea 
duniig tneir action. 

Reaching the thoracic cavity, 
the trachea divides into the right 
and left bronchi, one passing to 
each lung. The nght bronchus 
is shorter, ■wider, and more hori- 
zontal in its course than the left; 
it entere the right lung opposite 
the fourth dorsal vertebra, and 
divides into two branches. The 
left bronchus is narrower, more 
oblique, and longei'than the right, 
being nearly two inches in length. 
It enters tlie root of the left lung 
opposite the fifth dorsal vertebra, 
oi- about one inch lower than the 
right bronchus. It divides into three branches. 

Both the gieat bronchial tubes, like the trachea, consist of 
rings of cartilage united liy a membrane composed of elastic 
and muscular fibres. Tlii:^ form of construction is retamed un- 
til they reach the luugs, and sultdivide into the branches which 
pass into the lobes. 

Tlie Itronchi continue to subdivide after they reach the lungs, 
until finally tubes of very fine calilire are formed . these are 

,lled capillar}' bronchi. Each capillary bronchus terminates 

a cluster of air-cells, which form a lobule. The bases of the 
lobules ai'e marked by the network of lines which is visible on 
the exterior of the lung. Fie.w, 

The cells of the same lobute 
intercomnumieate free]y,l)ut 
the cells of difi'erent lobules 
can only communicate 
f through their respective ca- 
pillary bronchi. 
■ In Fig. 97, a represents 
N;be natural size of the sec- 
■tion of lung tissue which is 
nagnified "J diameters at h, 

'-cellb? What are 







106 



THE ANATOMV Ol" THE LUNGS. 



to illustrate tbe air-cells, c, and ^ 
t-apilkiy Itromlii, ?. 

Tlie air-celirt vary in diameter 
frmii jJk to -jV of an inch. They 
arc fiiii]p<jscd of a meinUiiuiHU!! 
ival],fiiniii*he(i with iiivolmitarj- 
iiiiiscle-cells, and lined with mu- 
I cmi^ luciiiljraiie, which is pro- 
vided ^vitli ciliated epithelium. 
On the walls of the cells, and 
Iictween them, the capillary vc* 
^ n.-h of the pnlrnonary nysteni 

™^ """ are distributed : they are about 

j-jjnit of !in incli in diameter, so that the blood discs can pass 
through with i-oniparative freedom. 

ifg_^ The lungs are w>ni- 

ix>seil of the lnT>nchi, 
air-eel Is, and bloo4l-ves' 
sela. They are placed 
(HI the sides of the 
thoracic cavitj-, the 
heart lying between 
tiii'in. riicy are near- 
ly conicAl in shape, 
:!!(! lu'ld in jio^itiuD 
\ the nK>tji, which 
I' attached to their 
iuiicr t-idt«, and are 
lintin-il t>f the lai^ 
limnchial tubes aod 
blotid - vessels wbidi 
■ enter the organ. The 
' right lung \s divided 
into three- lobes, ami 
J the \v(t into two. The liver enontaches on the right lung, rvD- 
i dering it shorter than the let^ ; but sim**- the heart lies chiefly 
I on the U'fl side, the left lung is suudlcr than the right, tboapi 
^it U lon^-r. 

The Mdes of the thoracic cavity which contain tht^se oi^;aiu 
aiv ct>ui]H>!«ed of the rilw* and iiitennwual nuwcles. while tho 

'"D«rribe'iW«ir<^l«. Whm i. ilw .lUmf im -f ihr r«i«K.iff, .yfxhr yataimatr anart ■ 
Tinnihe ikf lungt. Whst ti thrir ru^>tiaii f OCuhii iin> ilw r«"» uO|K^p aaQBamlf 
Hiin mnny luba are then: )n llw nKhi luni;— >a J|^||ftf Whi*^^^^"^ toBCMtT 



I V' 



^ 





niE STAGES OF RESPIRATION: 107 

floor is formed by the diaphragm. A continuous serous mem- 
ln'!Uie liue!^ the thonicic walls, iind is reflected over the suiface 
of the luugs: it is called the pleuia. The jiortion covering the 
walls of the cavity is designated as the costal pleura; tliat 
covei-ing the lungs is described as the pidmonary pleura. This 
membrane gives the organs contained in the chest perfect fi'ee- 
dom of movement during inspiration and expiration. The ca - 
pacity of the liuigB is about gl>0 cubic inc]it;a . "* 



LECTURE XXII. 

THE KESriltATOltY I'llOCESS. 



The Quantity Introduixd. — The HUifftii of Respiration. — Action of the 
Jjuiiffs. — Diffusion of Gase^. — Mettil^'aties and Diffusion. 

The number of respirations is seventeen per minute - and in 

fjgkj^yjlmjii^i seventeen cubic T^cli es are introduced, which 
artlly suffices to till the hirge Ijronelii , 

Respiration cousists of two distinct movements; lid. Itiftpira- 
iion,])}- which the ti-esli air is introduced ; and, :?d. Eapi ration, 
by which the foul air containing the carbonic acid gas irhicli 
has been separated fiom the bhxid is voidetl. The act oF in- 
t>piration may be divided into three distinct stages : 

1 St. The wechmiwal nkige, in which the pressure of the atmos- 
phere is calh;d into jilay, and the air introduced into the large 
bi-onclii ; 2d. S,'//ij,/( diyf union, by which the fresh air is intro- 
duce<l into the br.nulii, and pasnes into the air-cells, while at 
the .«anie time foul gas pusses outward ; Jid. Diffmion through 
wtmhi-aneH and liquids, by ivhicli the oxygen introduced into 
the air-cells passes through their walls and those of the blood- 
vessels to reach the ])lasma and blood disca 

In /'/>/. 11)0, page 108, r' r represents a jar, through the upper 
opening of which a tube, a, passes, which is open above, but at- 
tached Ijelow to a bladder, h. The jar may be regarded as rep- 
resenting the walls of the thoracic cavity, the bladder the lung, 
and the open tube the trachea, aftbrding a free communication 
between the interior of the bladder or lung and the open air. 
Placing the apparatus in a larger vessel, '/, filled with water, the 

Whnt I isailPB compose the wnlls of llio thomcic ciivilj? WKni mombrnne lines llie CBTitj ? 
How is ilie portion tlint cm-ers flic lunR desij-natcd ? Wlmt is tlio capBcilj' of llio lungs? 
Hoif rnniiy rwpirntions in onn minulc ? How mnny cnbif inclics in cnrli 7 What aro in- 
i>t<itittion iinU expiration? What arc the alBges of ingpitBlion? How nnj Ibc firit imgc be 



SISrPLE DIFFU8I0S. 




lower opening of the jar is closed liy the- 
fluid in the same mauner that the ilia- 

ehrsffm closes the lower part of the chest 
iy Bitcniately raisinfr and depressing the 
jar, we increase and diminish its capMcitj". 
ami cause tlie bladder to expand and con-, 
tract, imitating the analogous movements 
of the iliaplnai^i, which, as it conti-acl!* 
nnd relaxes, inci-cases and diminishes? the 
i;i).;u-ity of the thorax, and causes the 
Uuii^s to collapse and expand. 

As in the preceding experiment the 
Madder acts in a passive manner, Mulmiit- 
ting itself to the etfects of change in press- 
ure, so the lung also acts passively, allow- 
ing the air to flow in and out with the 
movements of the diaj)hragm. The tissue 
composing the lung consists in part of 
elastic fibre, which assists to a slight ex- 
tent in emptying the oi^n of its con- 
tents, but, with this exception, the move- 
raents are purely passive. 

The amount ot compression and exhaustion exerted by the 
action of the dia]>hragm is far less than is generally euppoeed,' 
being equal to about half an inch of water in each direction, of 
'*""' iiit'h total variation from the extreme of ordinary 
inspiration to that of expiration, as may l>e demon- 
stnitcd by breathing ■with the nostiils open through 
a tube of large bore, one end of which is held looHcly 
between the lips, and the other placed imder the su^ 
face of water. 

The second physical i)roperty to which we shall 
draw attention is the pnncijtle of diHiision ofgasei 
^, If a jar is fillt'd with va]H)r of ammonia by moisteninc 

b ^ its sides with that rtuid.and jilat^rd mouth downward 
H J I over another jar which has Wen tilled with vapor t^ 
■fl hydrochloric acid in a similar manner, the light i 

H^ I f»r vapor in the upper jar passes do^\-nwanl into tl 
^K J contained in the lower jar, and, mingling with it, pro< 
^■"^ (luces a white cloud of sal ammoniac, w£ich is equally 
8iai|.ij.^i»mi jjg-jjgpj throughout both vessels. 



DIFFUSION THROUGH BARRIERS. 109 

To this phenomenon the name of diffusion of gases has been 
given, and it is shown by all gasea that have been eubuiitted 
to expeiiraent. It is not piwluced by gravity, but takes place 
asainst it, as vras demonstmted in the expennient related 
above, where the light gas moved downward, and the hmvy 
one upward, in order to produce a uniform mixture. 

By virtue of this principle, the jiure air which was intro- 
duced by the fii-st or mechanical act is carried into the air-cellp, 
and tile carbonic acid of the cells at the same time 
passes outward, to mingle with the air in the 
bronchial tubes, and be ejected by the act of expi- 
ration. The introduction of fresh portions of o.\y- 
gen into the cells constitutes the second stage of in- 
spiration. 

Not only vrill gases mutually diffuse when they 
are freely exposed to each other, but the same effect 
is produced with equal or even greater facility 
when they are separated by a mend>rane. 

If the pomus jar, a a, in the figui-e, is filled with 
air, and then covered with a vessel, c c, containing 
CI nil gas, the contents of the porous jar are_gi'eatly 
increased by the passage of the gas through its 
walls, as is shown by the fluid in tlie glass tube fi, 
attached to the jar, being depressed toward (f. If 
the vessel containing the gas is removed, the move- 
ment immediately ceases, and then commence 
the opposite direction ; the gaseous contents of the 
jar duuiuish in volume, the fluid rising in the tube 
to occupy the vacant sjiace. p,^ 

Through the walls of poreless struc- 
tures the same movements of gases occur, 
as may be demonstrated by taking a botr 
tie, a a, moistening its inner walla with 
aqua ammonia to fill it with the vapor 
of that liquid, and then blowing a soap 
Ijubble, r, in the interior of the jar liy 
means of a tube, b, loosely fitted to its 
mouth by a curk. If to the open jiro 
jecting end of the tube we appniaeh the 
-stojiper of the hydrochloric acid bottle mm 

kHow ion gravity influcnm tlio iliffusicin of bmcs T IIoiv k the wronil woge nccomplish- 
T| Whnl i» ihc influence of iniprji"Kiii(' mciiihr«npii nn tlia (IHTnMon nrgiucs? EnpUio 
frajMriment with tbu poruiis jnr. K^tjilnin iliu rx[ipHnK'nt wiib tha lunp-bnbblc. 








110 



DIFFUSION AGAINST RESISTANCE, 



as .soon as tlie luouth in removed, we find tliat n cloud of clilo 
Fi«.\<H. ride of amrnouium is produced, wjiowiiig that tlie amnio 
iiucal gas oontiiinfd in tlie buttle lias passed tliiymifU 
1 the walls of the Imbljle to mingle with the gases fm 
the luuga which it eoiitulned ; and, i-eaehiii-; the ojx 
extreiuity of the tube, its presence is indicated by the 
test employed. 

The force with which a gas will penetrat'' iiiniiy 
thick, pti-ong, resisting membranes is perfectly irrestst 
ible. The experiment,/'/!/. 104, consists in taking a 
stout tube of glass, a b, through the bottom of %*-blcli 
a couple of platinum wu-es, 7» c, pass, which can at 
]i]easure be made to communicate with the poles of a 
\'oltaic battery. The tube is partially tilled with wa- 
fer, e €, and a pressure-gauge, ^, and suitable stmid i>r 
,! il -iipport introduced, on which a slip of pajier moisten- 
jMD id with nitrate of lead is placed. The mouth of the 
i^WKf apparatus is then closed with a stout piece of India- 
"ig^iin™ rubber, a a, and the jilatina wires are brought in eon- 
prHniire. ^^p(; With the polcs of a Voltaic battery. Tlie passage 
of the electric current causes the water to uudei^ decompoM- 
tion, hydrogen and oxygen being evolved, which, since their es- 
cape is prohibited by the India-rubber, exert pressure, as i» 
shown by the rise of the index tluid in the pressure-gauge. 
WJR-n a pressure of five or ten atmospheres is reached, the In- 
di;i-nibl>er is covered by ft jar containing sulphureted hydro- 
gen ; tlie gas in an instant penetrates the membrane which sep* 
arates it from the gases contained in tlit; tube, to unite nitn 
them, its passage and presence in the ndxture of oxvgen and 
hydrogen being indicated by the blackening of the slip of pa- 
per. Increasing in other trials the pressure in the tube, the 
movement takes place with equal facility; we therefore con- 
clude that pres.sure does not influence the diffusion of a ffi 
through a membrane. 



Cllll picssuic ii 



X- dilfusioii through mcmhrucicg ? Uvw maj it be ilcu 



COMPOSITION OF EXPIKED AIIL 



LECTURE XXin. 

RESPIRATION — Co/Ul/l Ued. 



Second and third SlOffea depend on Ififf'iuion of Gases. — Stages ofSitpira- 
tion. — Ififference between inspired and erpired Air. — K^rperitnents on 
liespiratioit. — Object of .Reepiration. — ZHaeases offecthiQ the Jiespiralory 
tiystem. 

TcE experimeuts we liave related furnish us witb tLe ex- 
planation of the movement of the air from the air-cells to the 
blood discs. The tissues or membranes through which it is 
obliged to pass are exceedingly tliin, being the delicate wall of 
the air-cells, that of the hlood capillary, anil the blood disc. 
Tlirough these the oxygen passes instantaneously, and, reaching 
the hBeiuoglobin, is dissolved by it, and changes tlie color of 
the disc from dark to bright red. 

y At the same time, the carbonic acid, which has been held in 
solution in the plasma l)y the aid of ])hosphate of soda, is 
suirendered to the air-cell, and carried tmt of the system by a 
movement the inverse of that which introduced the os)"geu 
gas. 

If we allow atmospheric air to come in contact ^vith llrac-wa- 
ter, it will, after the lapse of some hours, produce a pellicle of 
carbonate of lime on the surface of the liquid ; but if we jinss 
the air from the lungs through another portion of the same 
specimen of lime-water, it immediately prochices a copious jire- 
cipitate, thereby demonstrating that the expired air contains a ' 
far gi'eater proportion of carbonic acid than atmoKpheric air. 
By careful elieniical analysis it is found that air contains only 
one part in tMO thousim d of carbonic acid , uliile the expired 
^a^e^xmtani IV(.iiiitIiree to tour per eeni. With the increa,se 
of the carbonic acid in the expired air, there is also a diminu- 
tion in the proportion of oxygen amounting to four or six per 
cent. 

Some years since I made a series of experiments on the func- 
tion of respiration, which are of intei-est, as they deal with eer- 

Aii|ilj the iirineiplpn of ili (fusion to the introduction oroxvffcn inlo ihc blood disce. Wlinl 
nn the mitecs of cxpfnilion? Whnc is the ititTnrcnco between inspircU Hnd expired uir? 
How mBJ it be dennniRlralnd ? Whal is Iho proponion of cnrbonic ncid in fnisb nlmoBpher- 
ic air? What IE I ho pvrcctitiigc in expired air? What a the loss of oxygon in expired nir? 



EXPERIMENTS ON RE5PIRATI0K 



tain points, such as the quantity of air introduced and the 
amount of moisture exhaled through thie channel ; they were 
published in tlie New York MtdiatI Times for Jul j", 1 850. The 
questions which that article discussed were, 

1st. What is the quantity of air exhaled in one mioute ? 
till. What is the influence of rapidity of respiration upon this 
quantity I 

3tl. What is the amount of water excreted by the lungs itt 
one minute ? 

4th. What is the influence of the rapidity of resj)iratorT 
movement on this quantity ? 

Many solutions have been given of the above in<iinries, fi-oiii 
the long-received assertion that there are seventeen respirations 
in one minute, and seventeen cubic inches in each, to the recent 
experiments of Vierordt, ^vhicli sho«- that there are sixteen res- 
pirations in a minute, aud thirty and a half cubic inches in 
each. Nor is it difficult to account for the great di.scre]iancies 
whicli occur in these statements, when we consider the manner 
in which some of the experiments were made; for example, iu 
determining the amount of air, one method "was by l)reathing 
into a graduated gasometer, and dis])laciDg the water contain- 
ed therein. But when we i-ecollect that the normal disturb- 
ance of pressure taking place during placid respiration is equal 
to only one inch of water, we see now gieat an influence this 
method of pertbrming the experiment would have in falsifying 
the results. 

Another element of eri'or was the dura- 
tion of the exjwriments ; in some, the 
quantity contained in a single e.xpiration 
being detenuined, while in those of Vie- 
rordt, whicli are the best we ha\'e, the time 
was only one minute. 

In order to avoid these sources of error, 
the appamtus Fig. 105 was resorted to. 

The air, as it escaped from the moutb. 
was conducted into a metallic ves8el,kept 
at 32° Fahrenheit by placing it in a mix- 
ture of ice and water ; here its moisture 
was deposited, on account of the decreased 
temperature. A thermometer was placed in the tube which 



mining iheqnnniiif or 




EXPERIMENTS OS RESPIRATION. 



113 



carried the air out of this condenser, as we may call it, aud thus 
the temperature of the escapinj^ air was known. 

It is evident that by the use of such an instmment all error 
caused by the intluence of pressure was avoided, for it required 
DO more eftbrt to expel air through its cavity than it does to 
drive it through the ti'achea and the naiTovv chink of the glot- 
tis. From the increased weight of the condenser, tlie amount 
of water collected during an experiment was deteninned. 

Having obtained the weight of water, and the temperature 
of the air a.s it escaped from the condenser, it remained to de- 
termine the dew point of the air as it escaped from the mouth, 
when, by means of the following ftu-mula, tlie volume of air ex- 
pired in a given time could lie calculated; As the weight of 
water in one cubic foot of air at the dew point of the breath, 
minus the weight of water in one cubic foot of air at the tem- 
perature of that escaping from the condenser, is to 1728 cubic 
inches, so is the weight of water in the condenser to tlie quan- 
tity of air expired. 

In order to avoid the error of time, which has entered into 
the researches of other observers, each experiment was contin- 
ued for the space tif twenty minutes, and from this tlie amount 
per minute was calculated. Having thus avoided the most im- 
portant causes of error, we proceed to give the results of some 
Ibservations made upon the above priaciples; and, 6rst, 
Of t/ie amount of Air expired in one Minute. 
Number of impiralions in ono tninnle, 16. 
Dew point of brcnih, 04°. 
Expci'imcnt I G19 cubic inches. 
" 3 GI8 ■' 
3 eiu '■ 
ft":;:.::::::::;:::::"::":;;::":;:::::::::::::::;:::::;" eal ■■ " 
ATcrnge per rainulc C22 " " 
Volnmo of uach respiration 38.8 ■■ " 

From thU we find that when respiration was carried on at 
its normal I'ate of sixteen movements in a minute, the experi- 
ment lasting for twenty minutes, 622 cubic inches were exhaled 
in one minute, and 38-^ cubic inches constitute the volume of 
each respiration, representing the physiological condition of the 
function. Let us now see the influence of decreased rapidity. 

In order to obtain a minimum, I breathed during the same 
space of time at in the foi-mcr experiments, but at the rate of 
only six movements in a minute, each act being as much retard- 

, At iho rate of (ixlecn respiraiioni per minute, what it tlie amount introduced at each in- 
n br tbb incthoii ? -» 




114 EXPEBIMENTS OX RESPIRATION. 

ed as possible, thus seeking to obtain the smallest anoonnt of 
air Avhi(.'h would satisfy the system during a somewhat leDgth- 
ened period of time. The results of the oliservations were 
follows : 

Xniiibcr uf rcspi rations in one oiinucc. 6. 
Experiment 1 fiOS cubic incht*. 



ATCrage pcrminuEc Gil " " 

It still remained to detemiuie the amount exhaled when res- 
pii'atiori i« huiried, and each act as full as it is possible to 
make it imder such circumstances, thus obtaining the greatest 
volume of air that can be introduced into the lungs per minute^ 
the experiment beiug continued fur twenty minutes. 

The result of one trial gave the following : 



From the foregoing i-esults we obtain the following table : 

Ksl «f ItaplnilMit. Cak In. rm ^ 

0. I^Kst nmounl suffidnp (br wants ottjsum ^ Kll 

16. AvoTDEc denmnil „ BBS 

33. L'uuiwl exltrnl uf nspiralorr operation lOTT 

From which we conclude, 

1st. The amount of air in each normal respiration is 38^| 
cubic inches, the nimiWr of acts being sixteen per minute. 

•2i\. The amount of air introduced uilo the s^-stem dejwnda, 
tor the most i«irt, on the rajiidity ^vith \vhiefi respiration is 
cju'rit'il on. 

<y thf M'at^r efhaM in one Minvt^. 

For the sttlntion of this pmblem the same instruoieDt was 
U'«tHl as in the e.\iH'riineiit* given above, and the method of' 
pitHtHlure was the same. 

The results of fi>ur ex|H'riments were as follows : 

Graiui oTtiMer pn- Mtottie -..-™ *.»78 



J£y«y f^fln-r^t^ lit Kaftitlitjf t^ Jforttment. 



I 



EXPERIMENTS ON KESPIRATION. ] 

Effe(:t of increased Mapidity, 

Nnmbw of rcspirBlioM per minntc, 33. 
Expedmcnl, Grains per minute. 7.660 

Tabulating tliese experiments, we obtain : 



\ 



No. oT rcBinrnlioni, G. Graiiit of wnler per minuti?. 3.58li 

" " 18. ■' " ■' *.*!6 

33, " " " 7.560 

From this we find that the quantity of water exhaled also 
depends on the rapidity of the respiratory act. 

These e.xperimenta were all continued for the same period, 
viz., twenty minutes. They were all niad(* at a temperature of 
5G°,and a dew point of 49 . The same person was the subject 
of each experiment, being a healthy adult weighing 130 Iba; 
and the results may be summed up in the following general 
eonclusions : 

lat. The number of expiratory acts being sixteen per minute, 
each contains 38-]^ cubic inches of air. 

2d. The amount of water exhaled in one minute at a temper- 
ature of 56°, and a dew point of 49°, is 4^*oVo grains. 

3d. The amount of water and air exhaled from the lungs is 
for the most part dependent on the rajndity of the respiratory 
act, incre-asing and diminishing therewith. 

From tlie facts we have given regarding respiration, the 
reader will perceive that it must perform some function of 
great importance to the system, for if tlie lungs cease to act but 
for a few moments, death is the result ; if we breathe a gas that 
is noxious, or air that contains but a wery smalt prop<Jition of 
carbonic acid, we die. 

Recalling the mechanism of the lungs, and the change im- 
pressed on the air wliile it remains in them, we can not avoid 
the inevitable couclusion that the duty of these oi^aus is to in- 
troduce o.xj ^en into tjie sv?tem,^audj¥moje_m;]joiii£^,gyd. 

In a previous lecture attention was drawn to the fact that 
many animals not only iiialntaiu a temperature higher than 
that of the medium iu wliidi they live, but they also possess 
the pow(Jr of keeping it at a fixed degree. This can only be 
done by means of an oxidation iu the system of carbon, hydro- 
gen, and other substances, and it is tlie function of respiration 
to introduce the necessary oxygen from the au*. 

How docs ihc niie of inspirslion nfft'ct llic unnnllly inspired? Whst is Iho nmoum of 
■noislnrc piiven otTliy t\\v liinm? Wlinl imlie influence i>( incrcatied rnpidiiT nf re^ir«lion ? 
Wh»l is ilic funciidii of rcfpirnlion ? Wlint focts niRv be advanced to prorc ihese siaie- 



116 DISEASES OF THE RESPlBATOttY APPAHATCS. 

Other gases, with the exception of protoxide of nitrogen, w'tU 
uot answer, and even the i)mtoxide can only be used ibr b 
short time. We may, it is tiiie, tor a few moments employ by 
diogen or nitmgen, but they fiually cause death by acliug io a 

{)assive manner, and preventing the entrance of oxygen. Car- 
)ouic acid, and the great niajontj' of gases, are not only incapa- 
ble of supporting respiratiim, but also possess a directly poison- 
ous effect. 

Cai'bonie acid being one of the products of the action of oxy- 
gen on the tissues of the system, is, as we have stated, very 
jM>isonou8, and must thei-efore be removed as fast as it is pro- 
duced. Tills the lungs accomplisli by the act of expiration, the 
carlionic acid being held in solution by the plasma of the blood, 
and so conveyetl to the limgs as quickly as possible. 

Before closing the consideration of the respiratory organa, it 
la neci'ssarj' to make a few ivniarhs regarding the tliseat<es 
whicli affect them, since in our city a ver\- large proportion of 
the mortality is caused by the diseases of the lungs and their 
apfx-ndages, 

1st, Croup is an iufliminiiilion of the mucous membrane of 
the hirjnx and tipper parts of the respiratoiy tract, attended 
by the exudation of lymph and tV>rmation of a false membrane, 
which j^-adually or suddenly doses the air-tubes, and so causes 
death; it wmu'times e.\tends down into the capillar\' bronchi 

2d. Jii-onrhitit is an onlinaiT inflammation of tlie mucons 
incmlii'uue of the larjre brtmchiai lubes, which terminates in the 
formation of pus. The nuiL'h is loud and ringing: the jiain in 
the fixmt of tlie chest ; the expectoration at first a white fi-othy 
luaterial, but finally purulent , 

3d. (lirouic Jiixmchitit is produced by the previous disease 
when it has contiiuui! for a h>ng time, and left the mucous 
membrane thickeneil and initabUv 

A\h. (\wUhtrti Ihtiiu'hilid nffeets the membrane of the fin^ 
allies; It IS daniTciitus. and causes great suflcrtng. 

flth. I'nfiintvuiif is an inflammation of the air-cells and tissue 
of the lung, stteuded by solidification and closure of the cells. 
It usujilly tomiuentH-ji «t the l>ase of the right lung, and is al- 
telideil by a dull sorenesA. ».x>ugh. ami the exjiectoratiou has an 
inm-rust oidor. 

ttlh. IVfu nsti is an inflmiunatiou of the serous memliraae 

lion iloDilruCFM mihI b)ili»»vii "C "" ih' •}«>■>«'' Ho* ilxv caiK.Bir BciJ mat Ham 
il lh« rarhiinir nciit |m«tlK>r>l in itw n.tiMvm oMui-jnl ■•> ih, Un^i Wluii u ci 
itb— «hRNi'K lin>nchit»r Wht im ciJU»r? bnMwktH.! WIim u 




ANUIAL HEAT, 117 

covering the Inng ; it is attended by aeute pain, so tbat the 
sufferer trie? to snppreS3 the oougli as mut^h as jwasiljle. There 
is no expectoration. It most frecjUfiitly ttTiniiiates by the pul- 
monary and costal pleura adhering; tu eiicli othi-r. 

7th. Consumption, also called Phthi-fis or 'fuberculomi*, usual- 
ly commences at the apex of the left lung, by the deposition in 
the tissue of the organ of small hard masses, called tubercles ; 
these gi'adually undei^o disintegration, and are converted into 
pus, which is expectorated, leaving a cavity. The great consti- 
tutional disturbance which accompanies the disease assists in 
reducing the patient, and death is hastened by the hectic fever 
and terrible ui^ht-sweata which often aj)pear in the early jjeri- 
od of the attack. 



LECTURE XXIV. 

AKBIAL IIEAT. 



^H^ntfion of Animal Heal. — Pai/ie's ExpeHtnetita on the Temperature of 
^^B Plants. — Cold and hot bloinfed Animals. — Jie/atiun of tlm Aervons .S^s- 
^B.fe»t to th£ Peodvction of Heat. — AUotropio t'oitditian of Carbon and 
^H other EUmentarij Hubflaneee. — Bhtaliing eieptaiMd. — Variatium in the 
^P Temperature of the Jiody. — Temperaturat that can be endured bu the 
■■ Bodg. 

Br the term animal heat it is intended to express the fact 
that creatures, especially manmials, possess a temperature dif- 
ferent from that of the medium in which they live. In the case 
of plants it is sometimes higher and at others lower than that 
of the air; this Is in part due to the fact that the woody fihi-e 
of which they are composed conducts heat with greater facility 
lengthwise tlian crosswise. The interior of the stem of a plant 
therefore follows the temperatui-e of the soil in which its roots 
are placed more closely than that of the air. 

In his Medical and Physiological Commentaries, Professor 
Paine gives the results of experiments on the temperature of 
plants, which demonstrate that these organisms generate a cer- '' 
tain amount of heat within their systems, as is shown by thai 
following table ; 

TcmjKraliira of ilic nir in ihe shnde, 83° to 62°. 
TDTtiperntnro of n dond iree, IS iiichcn diamoicr, 15". 
Tcin]>crnturo of Jiigliins eqimmoso, 10 indies diameicr, bodi 





L WliAt is contiimplion ? Whnt ia munnl hv nnimiil livut ? How mny ihQ iniertial lempcr- 
« of pl*nl> be in pnii nccountcil for? Wiiiit wns itie rosuU oFProfeaior Paine's eitpori- 
il icmiieraiuru of [ilunts? 



OF COLD-BLOODED A51MAL8. 




Tempernlnro of Qncrcns liiicloiili, 7 incHca dinmelcr, no budding, 49°. 
Tempcroturo of CiiBiHnoa Amcriuinn, 12 incW diomotcr, no liudding, 60^. 
TcinperHture of Sulix Baliyluiiii-a, 1 H iiichea dinmelcr, hiids uiifutdod, SS^. 
Temperature of I'iiiii* L'nnndcriBi*. IS iinlii^o JiiimcUT, fi*'^. 
Temperatiirc of Jaiiiporus Virgiiii»ii;i, 1 IikIil-s duimtfer. .'.."lO. 
TetDpemtnre of PoimlualiBvit'iiin, 4 im-lita (liiiiiiclci-, in bloom, 02°. 
Tempcralurc orropnlus iKvignlii, '.i imlu's .Iwiiii'tor, in liloom, &*>", 
Tempcrniuro of I'opulus lieviKULa, :j iiid»dBdiHiiitu-r, in bloijiti, 67". 
Tcmiicruturo of I'upidiis lievigulii, 1} inches diiimclor, in bloom, 68°. 

*"'=■ "*■ Passing from the 

vegetable to the 
animal world, we 
find that the lowtt 
forms of animals 
have a temperature 
"""^^'^ but littlt! liigher 

than tlie water or atmofipher« they occupy, and 
ivith the rise and fall of tlie temperature of the me- 
dium there is a corresponding and almost immedi- 
ate change in their temjierature. All the animals 
that present these peculiarities apjiertain to the 
cold-blooded class, which includes iishes and rep- 
tilea. In these creatures respiration is either ao 
eomjdiahed l)y the skin, by gills, or by rudimentary 
lungs. 

Cold blooded animals, as a rule, are far more te- 
nacious of life than those which are hot-blooded; 
they breathe more deliberately, and their tissues 
wa§te away far less rapidly, so that they can live 
for very considerable penods \\ ithnut food. The 
amount of nutriment consumed ^^\ them in a given 
time is much less than that re((uired by a hot-uiood- 
ed animal of equal weight. Culd-blooded creatures 
can also sustain \vith comparati\-e ease injuries 
which ^vould almost instantly destroy the life of a 
bird or besist, and they sometimes reproduce an tn- 
tire exti-emlty tliat has been lost. 

Men, beasts, liirds, and all hot-blooded creatures, 
possess the poiver of maintaining their temperature 
at a iixed degree. The resi)iratni-y apparatus reach 
Lung,.fi.fviii=. g^ perfection in them; tlie lungs are more tho^ 
oughly dirided into air-cells ; the rate of respiration is more 
rapid, and the pulsations of the heart are more frequent, so 

Whnl is n col>1-b1i)ndcd animni ? Whal ii n liol-blnodcd nnininl ? How ii irtj.irntinn 
Mtmplishcd in cold-blimded «niniok ? Wbicli rlnra of nnimnls nre iho mosi tcnodmu «f KAI 
In wbiL'li cl«99 ornniinnls is the resiiiratory apporaius moit ]icrfci![? 



TIIE OHIUIN or ANIMAL ITEAT. 



119 




Ijingotilir Vns. 



that the hlood is passed in a continuous 
copious stream through the capillaiies. 

It has been already stated that the or- 
igin of the heat in the system was the 
union of carbon and hydrogen with oxy- 
gen; to this we must add the oxidation 
of the sulphur of the muscular and the 
phosphorus of the nervous tissue, though 
the proportion derived from their coni- 
busfton may be disregarded when com- 
pai-ed with that obtamed from carbon 
and hydrogen. 

The oxidation of combiistible sub- 
stances goes on to a certain extent in the 
lungs, but the chief action is in the systemic capillaries, so that 
heat is produced in the innermost recesses of every tissue of 
the body. Any one who has ascended a lofty mountain will 
recollect the peculiar intensity of the cold, which seemed to 
penetrate to the very maiTow of the bones, when the tlierniom- 
eter did not indicate a degree of temperature at all commen- 
surate with the effect on the system. This is due to the fact 
that at great altitudes the air is rarefied to such an extent that 
each inspiration introduces far lem oxygen than is conveyed 
into the system at the level of tlie sea, conse(|uently there is 
a smaller amount of combustible oxidized; less heat is pro- 
duced in the interior parts of the body, and the sensation of 
cold is the more intense, because the actual internal tempera- 
ture is lower. 

Animal heat being pmdueed by oxidation, some process is 
necessary by means of which any excess of lieat may be con- 
veyed out of the system. This is accomplished l)v the evapo- 
iTition of water in the form of insensible perspiration from the 
skin and lungs, as was e.\]>lained in treating of tlie uses of that 
liquid in the system, water retjuiring an enormous amount of 
latent heat in order to eoiivei't it into the gaseous state. 

It wa^ formerly siij)posfd tliat the heat of the botly was pro- 
duced by the uen'ous system in some mystenous manner, but 
we now know that, though the nen'ous system does not oiigin- 
ate the heat, it regulates the rate of production. 



WhilE K the oriEin nf ilia liciil i: 
I liody? Wlij is sHcli nn intciiw At 
I Eovr is tlic vxcesB nf Ileal ]<nHliii'i'< 
i nemos lyttcro to thu protluciion u 



ihc syMcm ? Wlicre ilm-B oxidniioti Inke plncc In ill" 
:rpe nf mM (-xixTii'iii-ctl ill nsrcnJiiig; lofl; moiinliiilu ? 
in eIm Iwdv di-piiHiil uf ? Whnt ia Ihe Rlmion of ibe 



120 OAl'SES THAT INFLUESCi: TEllPEBATimE OF ANIMAIj^ 

Chemists have shown tliat oxygen, as well as carbon, hyditv 
gen, aiilphiu', and phosphunis, jjreseiit themwlves under at 
least two allotropic forms. In one they are prone to unite 
with oxygen, and in the other they are indifferent, and show 
little or no tendency to go into union. To tlie tb-st state tlie 
temi active has been applied, while the second is called the 
jjaBsive condition. 

Electricity jwissesses control over the condition of these bod- 
ies, and can convert them fi'om one state into the other. The 
nervous force likewise can influence the allotrojiic condition, as 
it ia called, of these elements. Whenever, therefore, the atoms 
of carbon in any given tissue are changed to the active form, 
the flow of discs to supply them with osj"gen is immediate, 
heat is evolved, and carbonic acid produced. In this niauner 
such sudden congestions of the oapillai'ies as that which occurs 
iu lilushing are readily and rationally exjilained. The true re- 
lation of the nervous system to the protliiction of the heat of 
the body is similar to that which the engineer bears to his en- 

g'ne; he does not produce the heat in the furnaces, but regn- 
tes the rate of production. 

The temperature of various orders of animals and birds is 
determined to a great extent by theii' activity. As an exam- 
ple, the swallow, which spends houi-s on the wing, catching the 
flies and other small insects on which it feeds, haa a tempera- 
ture of 110", while the barn-yard fowl, which scarcely ever soar? 
higher than its favorite evening perch, has a temperature of 
about 100''. 

In man the average temperature of the body is 98° ; but it 
varies in its different parts, deci-easing as we pass irom the cen- 
tre of circulation to the extremities. In the viscera of the ab- 
domen it is 101°, while in the leg it is 93°, and in the sole of 
the foot only 90°. 

Age also possesses its influence. At birth the temperature 
is about 100 F., or the same as that of the mother ; it quickly 
falls to 911° F., but soon rises to 102°, at which point it remains 
throughout infancy. 

The variations of temjK'ratuiv to which the human body can 
be subje-cted A\'ith impunity are far greater than is genei-ally 

ihc iirn nitotnipic fonnsT Hon |i iho allotrKiiU coiuliiton oF an clcmetiuiT 
trd I'V cWirii-it r T Crni tho nBirout fMXvcr itifluonc« ilic Blliiiro|iic Mndltioa'l 
■islimp he pxplninHT How iloii Ibfl nclirilvornn Rnimitl tnHuencoiU lenpfr- 
int i« tlip Avongt icmpenitupp of ninn T Wh«t i« ilic tffcre i>r<]isiane» fmin lb* 
ro of dreulotioa on tba ie)n|icniiuK ? llovr itws np^ influciiTp the KinpcnniM of iba 



r 



DIVISIONS OF THE UKINAKT APPARATUS. 



supposed. The thermometer in the polar regions often indi- 
cates a temperature of — 60° Fabrenlieit, and yet a seaman will 
in the coui-se of a few weeks pass from regions in which mer- 
cury freezes, to the equator, where the temperature is 130° in 
the shade, without serious injury, though the change in climate 
ha.s amounted to nearly 200". 

Far greater variations than these can for a few moments be 
bonie. It is stateil that a man may enter and remain for a few 
seconds in an oven, the temperature of which is 600", providing 
the air is drj-. Under these circumstances, the rapici evapora- 
tion from the surtace of the body prevents the temperature 
■ "tising ; but if the air is moist, evaporatitin does not go on, and 
prions consequences immediately arise. 



LECTURE XXV. 

THE UniNAItY SYSTEM. 



tition mid Descriptive Anatomy of the Organs forminff the Urinarjf 
\By»tem. — Microscopic Anatomy of the Kidney. — Portal Cirrulalion 
tjf the Sidney. — TAe Malptffhian Tufts, Convoluted and Straight 
3.\ibes. 

• The third channel by which effete substances are eliminated 
from the system is the urinary apparatus. It consists of the 
kidneys, tireters, and bladder. The bladder is situated in the 
pelvic cavity, and is the receptacle into which the urine passes 
as fast as it is seci-eted, and from which it is voided at tlie de- 
sire of the individual. It consists of a muscular bag lined with 
luneous membrane, and, when distended, will contain a quart 
of liquid, or even more. When it is subjected to too great a 
degree of distention it becomes paralyzed, the muscular coat in 
some instance^* never regaining its pmper contractile power; 
the sufferer loses all control over the organ, and the urine drib- 
bles away slowly, causing great annoyance and inconvenieiica 

The uretere are tubes about the diameter of a goose-quill ; 
they pass from the bladder to the kidney. Tliere is one on 
eacn side of the vertebral column. 

The kidneys are two in number, one on each side of the 



I 



122 



TKE ANATOMY OF THE KU>SEr. 




sjiinal column, in the lumbar region or 
loins. Tbey extend li-oni the eleventh rih 
to the upper edge of the ileum, and are 
about four inches in length, two iu breadth, 
and one iuch thick. Tliey are sliajM-d Hlii 
a bean, and in the male adult weigh from 
4^ to (i oz,, in the female tiom 4 to ^} uk. 
The liithiey is covered pxternally by a 
K\ strong iibrous einelnpe, called tlie capsule, 
uvuv the antenor jioi-tion of whicli the iht- 
itnneiim passes, the jiosterior surface being 
iittiiclied liy cellular tissue to the waUg of 
tl]i> ;ilulnuiiiial cavit}'. 

Oil iiiiikliig a section extending through 

tilt' gi'eater diameter of the oi'gan, we tinil 

that it is composed of an external or cortical layei', 1 2, which 

in dark red in color, and about two lines in thioknesn, and an 

intcniiil or niedullaiy substance, 3 3, of a light red tint 

The ureter, (1, enters the kidney at the notch on its concave 
bordi'i', and expands into a couicul-shaped cavity, called the 
pelvis u »; i'lto this cavity all the mi- 
nute tulHw which form the cortical and 
medullary- jKiition of the organ eiupt)\ 
The small tubes of the kidney, oi- tn- 
bull uriuifeii, as they are called, com- 
mence in the eoiticid jjortion in a flack- 
like 1hm1v,A, called the Malpighian cap- 
Hide, which contains a tufl of l>lo<:»d- 
sele, fff It, and is lineil by spheroirlal ep- 
ith<'Ihmi,« r. Leaving the capsule, the 
tii-st pi>rti<m of the tulnde is twisted fre- 
nuontly on itself i!s Kmg as it i-emainsin 
the coi-tical itortion : it is therefore call- 
ed the i-onvoluttxl tube, B C, and is lined 
with spherxiidiU cells, h if. As 8tK»n a$ 
it ivaohes the medullary portion, the to- 
bull' pursues a slnuglit course until it 
empti^'s into the ]>eh-is of the kidnev- 
In Fiij. lll,rt ivpn-sents the straight 
tiilnw, which originate tV>«a the wnvolut*-*! tnlies A A, among 

IVirHbr itw |>>vllmii I'f ihe ltiliw(«. tlxtr *iw mi ^m^t. Whu b bhu bt tW u«.r 
nX Uhl amtnUart mtiKhm vi ih* kWwj ? WhM ia tbe frfri. rf ibe kiriiwi i ' Whu aw 




-«J^T 



Iwliich the ramifications of tlie renal ar- 
tery, c c', are shown, and the Malpijjhian 
tufts, c". 
The circulation in the kidney presents 
peeiiliantiea of considerable interest in con- 
nection with tlie tlieory of the eiix-nlation 
of the blood ; it is therefore worthy of es- 
pecial study. 

The renal arterj', as soon as it entei-s the 
>rgan, coramences to subdivide until the 



THE BLOOD-VESSELS OF THE KIDNEY. 






UuDrolulod Tiiha ■nil E 

branches, a, I<^. 
113, are almost ca- 
pillary in their 
character. One of 
the minute branch- 
!, fl /, entei-s the Malpighian capsule, and, subdividing into 
iiall braiK-lieH, which are convoluted or twisted on eacli other, 
IfuriLi-i tin- ^Miiljiighian tuft, ?». To the arterj', as it enters the 
\ caiisiilc, the name afferent vessel is given. The branches which 
form the tuft reunite and form a trunk, which takes its e.xit 
from the capsule close to the entrance of the afferent vessel. 
It is called the efferent vessel,*;/^ 

As is demonstrated by the figiu-e, the efferent vessels do not 
tnite immediately to fomi the renal vein, but pass to the con- 
fc-oluted tubes, and, subdividiiig, form a capillary system or 
plexus, ^j, which covers their surface, and by which the sphe- 
oidal cells of the mucous membrane of the tube aie nour- 
bhed. These capillary vessels, reuniting, form the terminal 
fcwigs of the renal vein. The efferent vessel is the analogue 
ipf tlie portal vein, since it begins and ends in a capillary 
ystem. 

lloiv U iho renal nriery disiribuied ? Wliai is the effurent vesBel? Wliere docB Ihe renal 
lin cumitionco la form? 




LECTURE XXVI. 

ACTION OF KIDNEY AND LIVEB. 

Properties, Qwtntity, and Comp-mirion of lTrine.~~T/ieoi-r/ of the Action of 
uie Kidney. — Functions of tlte Liver. 

Urine, the secretion of the kidney, is & yellowish fluid, with 
n specific gravity of about 1025 ; it has an acid reaction, but 
soon becomes alkaline, owing to the decomposition of urea. In 
a day, the amount passed by a healthy man is about tliirtv-fivt^ 
ouDces . but this varies with the quantity of liquid"iinLit)eU 
and the amount of pei'spiratiou. 

The constituents of the excretion are all substances that are 
almost completely oxidized. Tlie uitrogeiiized group is repre- 
sented by urea and urie acid, derived to a gi-eat extent from 
the nitTOgenized elements of the food. The extractive repre- 
sents the respiratory gi'oup, and the chlorides were taken info 
the system in the same form they present in the ui-iiie. viz., 
common salt. The suljihates and phosphates are derived from 
the nmscular and nenous tissues, as is demonstrated by tlie 
feet that incTeas^ed action of tlie innscles and nervous s^ystem is 
followed by an increase iu the sulphates and jihosphatea. 



Wnler 

Urea 

Macui and qNiholiu 



Ano/jri. of tVi'-r bs ISaztliut 



SiUW) 
I. no - Niu-oecniicd .. 
32 i 



Extractive *iul InctatM..,. 17.14 Xon-niirogcniiMl 17.14 



ttulphatc or polRili... 

Sulphiitc of M>dii 

Pha8|iliBtc of ioda.... 
Bt-|ib(«pfaats of Rrnni 
I'hwphatB of lime nnd maBMtia.., 

Chlorida of Mdium 

Chloride of ammoninin 



^ llj- Sulplmtcs- 

3.'m> 

l.a'i-riioephatcs. 

l.oo) 

t'J^[ Chlorides ,. 



I 



HtOO,00 Snlids C7.00 

Wutcr 933.00 

lUOO.UU 

"With the exception of tlie e.\tractive, the snbstanc-es in the 
preceding table ai-e all nioiv or le.ss solul'le in water, and pre* 

Wbai U the color. itpociflc|piiviir, rcarrlnii,Bnd dinmnl nmnnnl of nrine? Does humnn arina 
nta'm the arid reaeikin aner it in jWMntr What gnuip* uf fixtd do the conttituenia nf tin 
urine rcpiVHnt? WfaalitlhecotnpoiiitiunortitliwT Whiehrantiiiueniipie-exhtinibeUaadT 



r 



METHOD OF ACTION OF THE K[DXEy. 125 

exist in the blood, as has Iwen satisfflctorily demonstrated. 
Tlie soluble ingredients ai'e easily separated by a mere ac-t of 
filtration, similar to tliat t-ondiRtcd in tlie sudoiipaTOns glands; 
and since we can witliuut <liflifiilty find in the sudonparous se- 
cretion the chluridcs, plmspliutcs, j^ulphates, and urea of the 
urine, we iuvpt tin: tliei.ry tliat these substances are sejiarated 
by the Miilpi'jhiim tuft, which is analogous to the sudoripar- 
ous gland ill lis structure as well as in its function. With the 
extractive of the unne the case is different; the substances 
composing it do not pre-exist in the same form in the blood ; 
they jmrtake of the fatty nature, containing a great excess of 
carlwn and hydrogen, and are devoid of nitrogen. Since they 
do not exist in the bliwd, they must be formed from it by cell 
action or in sonie other way. It \vill be remembered that the 
avails of the convoluted tubes are lined with spheroidal secre- 
ting cells, which are fi-eely nourished by the blood brought from 
the Malpighian capsule through the efferent vessel. It is the 
function of these cells to sepai-nte from the blood certain sub- I 
stances, which ai-e appropriated hy them, and converted inttfj 
the extractive materfal of the urine. n 

The convoluted iwrtions of the uriniferous tubes are analo- 
gous, both in their structure and function, to the sebaceoua 
glands of the skin, which also separate their oily seci-etion from 
the blood by cell action. The method of action of the skin 
and kidneys, therefore, is identical, except that in the skin the 
two systems of i^lan<ls are separated, while in the kidney they 
are united, tbrmmg the convoluted tube. The straight portion J 
of the tul>e merely conducts the fluid secreted by the Malpiglui 
ian tuft and tube into the pelvis of the kidney, and thenco^ 
into the ureter and bladder. 

The separation of the unnaiy secretion is continuous, and 
not intermittent, as might be supposed. The tufts and cells 
are never at rest fi'om the day of birth until death. If any 
thing occurs to interfere with their action, it is immediately 
shown by the Iduud-poisoning which takes place, the urea and 
extractive accumulating in the system, and producing coma. 
frhich rapidly proves fatal unless it is relievea. 

The action and function of the kidney may be briefly sum- 
led up as follows: The renal artei-y delivei's to the organ im- 



e ihey sppnrnteil ? Huiv nnci wlicrc i» Ihc ojirrnctiTO 
I lire anfitiiguas (o llii; ■'uiivululcJ Iiibca? Is Ilic srere' 
\e com J II lions or inlormiltcnt ? Wbal is ihc ctfcct o( a 



126 METHOD OF ACTION OF TITE KIDNEY. 

Dur^ilood, laden with urea and other deleterious ingredieiits. 
T^raouam' fiul)divides, until finally small arteries are formed, 
called tbe aft'eivnt vessels; these enter the capsule at the ter- 
mination of the uriniferous tube, and, dividing into capillaries, 
foiTu the MalpigJiiiiii tiitit, which separates the water, salts, and 
uitntiTfni/.fd constituents of tbe secretion. 

Frmii tlic ]\Ia]pighian capsule the hlood is brought by the ef- 
ferent vein, wliich passes to the walls of the convoluted tubes 
to foiTU a capiUai-y system that nourishes the spheroid cells, lij- 
which the extractive is secreted. In this capillajy systein the 
twigs of the renal vein originate, and the blood is retumeil in 
a purified contli tioii to the vena cava ascendens. The aqueous 
flnnl, " it^i Its i.l!ssolved salts, that was filtei^d thniugli the Mal- 
pighian tuft, ])assini; into the convoluted tube, washes the ex- 
tractive into the ]>eVis of the kidney, and tlienee to the blad- 
der, where the urine is ivtained, until the distention of the w 
gan and the pain |H'odiiced induces us to empty it. 

Tlie rapidity with which deleterious substances are con- 
veyed out of the system is shown by the faet that if a dose of 
iodide of jxitassium is taken, it may be foifnd.by suitable tests, 
in the urine passed ten minutes afterward. Not only are salts 
quickly i-emoved from the system by the kidneys, but ot^nic 
substances are also rapidly eliminated, tor we are all acquaint- 
ed with the peculiar disagreeable odor which one of the con- 
stituents of asparagus gives to the urine passed immediately 
after eating that vegetable. 

Urea is the most important of the constituents of the urine as 
regards quantity, forming nearly one half of the total solid resi- 
due; it has therefore been the subject of special examination, 
many supposing that it represents the disintegiation of muscular 
tissue, arising from the production of muscular fort* or enere;)". 
In my thesis for the degree of Doctor of Medicine, published 
in the New York JomTutl of Medu-ine for February, 1856, it it. 
shown that in all probability urea chiefly represents the excess 
of nitrogenized material consumed. 

That the muscle is not itself disintegrated in order to prtK 
duce motion has been proved by the experiments of Fick and. 
Wislicenus, who have demonstrated that muscular power arise* 
in the oxidation of carbon and hydrogen, the muscle btdug 
merely the appiu-atns in which this is done. 



Whniiitho fiinciion of ill e blaiMer? Gitb Mime nunpltc )1)usiniiiT« of the tnpiditjr 
which deleieriuiis snl»i»iK*« tn *KcreMd bj ibe Udn<r*- What opinkMU an h«U n( 
ihe origin of urea? 




THE NERVOUS SYSTEM, 



127 



The peculiar province of the liver, until quite recent times, 
was supposed to be the separation of bile from the blood ; but 
we DOW know that it has other and equally important func- 
tions to perform. While discussing the blood, it was stated 
that the fluid of the hepatic vein contained sugar, which did 
not exist in thatof the hepatic artery or portal vein. In addi - 
tion , t herefo re, to the separation of bile , this g land is also eii- 



gflged in the conversion of fat into sugarTui "vhifh form th e 
combustible is more readily oxidize d. Another function per- 
torraea t>y the liver is tne production of a peculiar fat called 
cholesterine, which is appropriated by the nervous system as an 
exterior non-conducting covering to the nervous filjres, and is 
known as the white substance of Schwann. 



LECTURE XXVII. 

THE NERVOUS SYSTEM. 



IFhosphoni.1 the special Ittgredimt nf Nervous Substance. — Production of 
' Nervmis Force. — G^ray and White Nervous Substance. — Thf. Ganglia 
[ described. — The Nerves described. — Dioisiotis of l/ie Nervous Mechanism. 
— 7R« Nervous Systems of the Lower Animals. — TRe Sympathetic Sys- 
' tern. — 77te Cerebro-sptnal System. — Thu Brain. — 7'Ae Spinal Cord. — 
I The Nerees. 
I Havino completed the examination of the organs of locomo- 
tion, nutrition, and excretion, we now pass to tlie study of th« 
nervous system, which regulates and controls their action. The 
peculiar element of nervous tissue is a phosphorized oil, or fat, 
the amount of uncombined phosphorus in which determines in 
part the intellectual power, as is shown in the following table, 
in which tlie brain of an idiot contained about the t^anie jiro- 
©rtion of phosphonia as that of an infant, while the greatest 
"^portion 18 found in that of the adult. 

From L'Htnlier. 





li^ln of inftat. 


at taalh. 


llfAdl.lt. 


OfA«a MIdlnL 


PhMphoni. 


9- 


165 


18- 


10 8fi 



, That nervous force is produced by the oxidation of phos- 
3jorus is demonstrated beyond discussion by the fact that any 



re iliB fiiiiciionFt of ihe 
n upeciul cnmpoiient or nerva 
M aubslaiice VU17 wilh nge ? 



ler? WliDt i« Iho runctiun of the nenoiiB tinsiie? ' 
i> inntler? How ilo«t iha proportion of pliosplioruB ii 
low \i nervoiu foi'ce produced? 



VARIETIES OF NEKVE-CELL9, 



thing which imjilies or requires the 'levelopment of nerrous 
force, as ajntimied muscular or mental action, or any powerfii! 
nervous affection, as grief or joy, is followed by an inci-ease in 
the amount of the phosphates in the urine. 

Of these facts auy one may satisfy himself liy i-esortiug to 
the tests given iu a previous lecture ; such experinienta, iimv- 
ever, are not needed, tor all persons must have noticed the euor 
mous deposits of pliosphatea in the urine ^^ ^^ 

passed after hard study, or any severe men- 
tal excitement. 

In order to favor rapid oxidation, and the 
imnieiliate removal ot the phosphoric acid, 
produced, all nervous tissiies, but more es- 
pecially those which originate the force, are 
freely supplied \vith arterial l)lood by an ex- 
tensive and intricate system of capillaiy 
vessels. 

Nervous tissues are composed of two 
kintls of materials : 1st. The gray or origin- 
ating substance; 2d. The white or conduct- 
ing substance. Gray nervous matter con- »»™*^k»mw. 
trists cliiefly of cells, which may be regarded ria, m. 

as being analogous to the cells of au oi-diuary 
Voltaic [jattery. 

These cells vaiy in form, as is demon- 
strated hy F/ijK 114, 115, 11 B. In the first 
there is only a single pole to the cell; in the 
second tliciv are two jioles: such cells are 
therefore called bijiolar cells; in the thii-d 
there are many (xdes or projecting piticesses: 
such celln HIV consetpientlv called multipolar. 
Though there is w givat a variation in the 
figure and number of (xdes attached to nerve- 
cells, tliev lut' all coustructetl of the same ma- 
terials, vJe., au t>xteri<ir envelope, which is filled 
with H granular su^>staniv, ct>mi>oseil to a 
gn'at extent of the phiwphtirixe*! oil or fat 
previously nientiouetl. 

In onier to construct n uer\'0H3 centre, a 
nuniWr of nerve-cells uiiire. their projecting 



R<i* b it iit«*nl that tho (wiiUlhm ofphwiihnnn oiicinatn iKrreat fon«; 
Ike rntirtion of ti«y unJ wWw norroo* «ut«.i«tK«? Wk«i b iho oonpouiMi oT tta ■ 
' T« wlwl pMI of M «lc«trkal RniuBliM uv iSrj a>wbca«u ! 



STRUCrrRE OF A GANGLION. 




poles or fibres interlacing and intertwining to form a com- 
pound cell or ganglion, wliicli is ths .counterpart of an electric 
battery. The ganglia are very namerous, being wattercd all 
over the body, but the largest are found in the cranial cavity. 
Many of them seem to be endowed with f<])etial i>r(tjierties, but 
the gi-eatcst proportion are engaged in onginatiiig the nervous 
force, and controlling the rate of waste and repair, and in regu- 
yig 11, lating the vigor of ac- 

tion of the vaiioiw 
glands, oi-gans, and tis- 
f-ues composing the sys- 
tem. 

lu the figure, d c 
represents the nerve- 
cells aixl fibres which 
foiTu the ganglion; a b, 
nerves comnmnicating 
with other ganglia ; c 
a c, branches that have 
originated in the gan- 
glion. 

From the ganglia the iienes take their origin. They are 
eoui}X)8ed of white nervous substauee, arranged in the form of 
tubes, covered externally with a layer of cliolestcrine, which is 
ii non-conductor, so that the nerve fibres resemble in their 
structure the wires of an electric combination, with their exte- 
rior non-cun(hicting covering of silk. 

The nervous mechanism in man and the higher animals con- 
sists of two portioDc, the sj-mpatbetic system and the cerebro- 






130 



TAUIATIONS IN TIIK NKltVOI.'S SYSTEM. 



apinal axis. In the very lo^vest fonus uf nuinmtwl creaturp? ] 
the sj-mpathetic system alone exists. 

Tig IIS. Flu. 119. Flf. I»\ 




S^ati) 



:Iia 



ArlinXLtT 



■egularly 
ly uf the 
animal ; in radiates they 
are arranged iu a circle 
amuiid the mouth ; in ai-- 
Krm.... iyitrm of Mtiim««. ticiilatcs they ave placed 
along the median line, there being often a pair of 
ganglia for each ring composing the creature, and a 
single ganglion at each extremity of the nervous sys- 
tem. 

Vertelirates possess a spinal cord and l)rain, which ' 
are protected throughout their whole extent by a 
covering of bone, and are frequently brought into coutmiuiicA- 
tion with the sympathetic or ganglionic system, wliicli la scat- 
tered throughout the botly, its hbres entenng into all the 
glands, beiiiij freely distributed to the muscular coats of the 
intestine, anil forming a network on the arteries. 

The conducting fibres of the sympathetic system are smaHer 
than those of the cerebro-fij>iual axis ; they also contain a num- 
ber of nucleated cells. 

In tlie following figure the distriliution of the ^'mpatltetio 
nerve to the various ore;ans is shown, together with some <rf 
the large ganglia connected with it: l,tlie eye-ball; 2, branch 
of inferior oblujue ; 3, branches of tri-tacial ; 4, ophthalmic gan- 
glion; 5, spheno-palatine ; 6, otic; 7, submaxillai-y and, 8, sub- 
lingual ganglia ; y, ex motor oculi nerve ; 10,facial; ll,glo8S<>' 
pharyngeal; IL*, right pneiiniogastric; 13, left pneumogaatric; 
14, spinal; 15, hypoglossal; 16, cervical plexus; 17, bracbial 



r«bro-«piiial n 



rm of nnrninj mnrhnnUm? How hit iIip enoglin nTTi>n(r<^ in m 
nii^iiUim? Wlwrv ia llie tympnihciii^? I>i>rB iti'mnmnnicaievi 
II? WhMUQ lUu ]iccaluiriiiw of ibc fibres of ibc ijmpktbctic? 




TIIE SYSIPATIIEllC fiYSTESt. 



131 



glia; 50, lunibo-aortic plexiie; 
plexus; 62, sptrmatie plexus; 



plexus; 18, intercostal nerves; 
li>, lumbar plexua; 20, sacral 
jJexus; 21, superior een'ieal 
ganglion ; 2i!, Jaeol ison's nerve ; 
23,0!irotiilbrancliofvi(lian;24, 
external motor oculi; 25,opb- 
tbalmic ganglion; 2C. branch 
to iiituitary ^lody ; 27, anasto- 
mosis ot' cervical ganglion with 
firHt cervical lieiTes; 28, caro- 
tid branches; 29, pharyngeal 
plexus ; .'JO, laryngeal l)rauch ; 

31, snpenor canliac branch; 

32, nerves of union of ujiper 
cervical with, 33, niidille cervi- 
cal ganglion ; 34, anastoinofic 
nerve; 35, recnnvnt; 3(», mid- 
dle cardiac; 37, junction of 
middle cervical and, 38, inferi- 
or cervical ganglia ; 39, branch- 
es to great vessels ; 40, branch- 
es to Buliclavian and vei-tebral 
arteries; 41, branch to first in- 
tercostal ; 42, cardiac ganglion 
and its plexus ; 43, 44, plexus- 
es of right and left coi'onary 
arteries; from 45 to 40, thora- 
cic ganglia; 47, the splanch- 
nic; 48, semilunar ganglion; 
49, lesser splanchnic; 50, solar 
plexus; 51,pneuniogastric; 52, 
phrenic; 33, gastiie coronary, 
54, hepatic; 55, splenic; 5^, 
superior mesenteric ; 57, renal 
plexus; 58 to 58, lumbal* gan- 
fio, 01, enlargements of aortic 
63, infeiior niesentenc plexns 



64, hypogastric plexus ; (55 to G5, sacral ganglia; 66, coccygeal 
ganglion ; A, heart, showing cardiac jilexus ; B, arch of aorta ; 
C, innominata ; D, subclavian ; E, infi-rior tliyiv)id ; F, external 
carotid; G, internal carotid; il, thoracic aorta; I, abdominal 

lorta; J, primitive ibac; K,intercostals; I^pnbnonaiy arteiy ; 

T, vena cava descendens ; N, vena cava asceudeus ; 0, pulmo- 




132 



TIIE CEREBRO-SPISAL SYSTEM. 



najy veins ; a, lacbn'mal gland ; h, siiljliiigiial ; c, siibuiaxillan- 
* gland; (^^, thyroid gland; p, trachea ;/', (es^iphagus ; jf, stoniacli ; 
A, small intestine; /, colon ;^', sigmoid flexure; k, reetum ; /, 
bladder; ?«, ureter; 7), prostate gland; o, seminal vesicles ; ^, 
tm deferens ; y, spermatic cord ; ;•, diajihratrni. 
fc. The synipatlietie is the ner\e of oi^anic life. It takes charge 
nf di^ffps tion, al>sorption, and cii'cuIa HoD ; regulates the rate at 
which the seoretions of the glands ai-e pi-oduced, and attends 
to the processes of nutrition, repair, and excretion. When the 
cerebi-o-spinal axis is at I'est, the great syiiii)athetic' is busy i-e- 
pairing the wear and loss which tlitj muscular ami other ti.><sues 
have undergone in the proiluctioTi of'motion or action. It su- 
perintends the Violative lite of the animal, and is never at 
I'est. 

Tiie cerebj-o-sjnnal system consists of the brain and the «i>i- 
ual eonl and nerves; tlinmgh it all the manifestations of ani- 
mal lite are originated and conveyed. It regulates the move- 
ments of the voluntary muscles, presides over the special 
senses, and furuislies the thought, ideas, and «-ill, which have 
enabled man almnst tt> annihilate time and spaci 

The brain is placed in the cranial cavitv; its weight is 
equal to about ^th of the total weight of the botlv. It U di- 
vided into two distinct por- 
tions, tlie cerebniiu, or greater "" "* 
brain, which is above, and the 
ct'lvbeltum, or lesser brain, 
whicli lies Wneath the iwste- 
rior part of the ceivbrum.as is 
shown in 7'7;/, li'i'.in which 1 
is the nu'tlulln ol)liini?ita ; 2, 
ponsvamlii; ;i, ceivbellum; 4, 
pneumogivstric lobule; 5, fron- 
tal ctuivohitiona; 0, jwrietal 
convohitions ; 7. (Ki-ipital c«m- 
volutiona; 8,fi8suiv of Sylvhis; 
9, !>, its branclu'S. 

The cerebrum presents exteriorly n smfju-e marked with 
cnned pnyecttons called the eonvolnti.insi. On making a sec- 
tion of the orgiui. we find that the interior jKirtion is composed 
of w hite o r wunl«cting nervous tissue, outride of which there 

Wlim i» rho fiinetion t>rilw sympii'l'Piiv- f IXiot ii irsi iliirini; . 
linn iif ih" cctTl>ro-Ma"Uv<>''tn ' Wh«li«trt» rumpuMi iV <vi,-i, 
i* ttN> wi-icM of ihs brainT What •!« (ho •lltioiuui 1/ tlw Lmini 
(iniuurilwKivlininiT U lh«|tn^«or iIk trhiu mbtlanco 




r 



w 



TItE BHAIJJ AND ITj MEMBKANES. 




I 



I 



is a layer of gray ongii 

ting material, liy tliio 

ing the external gray lay- r 

er into folds anil coiivolu- '^^ ' 

tions, an enoriuous surface 

is gained, on which ianunieFable blood- vess(?ls form a sheet of 

interlacing capillaries. 

Tlie niemltranes of the brain are three in number: 1st. The 
blood-vessel layer, mentioned above, which dips down into the 
spaces between the convolutions, to supply the gray substance 
fi-eely with }>lood : it is called tlie ma rimkj ' ; 2d. A serous 
membrane, which passes over the cunvolutuins, but does not 
enter the dejires^sions. Like other fieruus membraues, it form.'j a 
sac and contains fluid, so that the brain rests on a water cush- 
ion, which protects it from violence, and equalizes pressure : it 
is called the (j^w^^iflij/. The third inembi'anc nourishes the 
bones of the cramal cavity, and ia called the <Mx\{ \{>iiii'>- ,' it ie, 
in reality, an internal periosteum to the cranial bones. 

The cei'el)ruin is divided laterally into tw.o parts, called the 
right and left hemispheres, each of which is subdivided into an 
anterior, middle, and posterior lobe, Fixim the Ijase uf the cer- 
ebrum, on each side of the median line, the ci-anial nerves take 
theii' origin, and pass to the various organs with which they 
are connected. 




\* gnincd by the ronvolulions iiilo nliicli iho pi 
1 neipbrnncaurilie brnin ? Dcscrihc llio pijt 
^dnnt raster, Wh«l nro lliu suUiTlsions uf ihu LureLruni? 
Le tiicir origin? 



ipr is ilirtran ? Whni nra il 
ihi! ni'BclinoiJ? 1>c«cril)i.' \\ 
Where ili. Ihc rr.mi:i1 iicm 



rs 



134: THE DIVISIONS OF THE BRATN. 

In Fig. 125, a is the htim. 

anterior lobe ; v, middle 
lyl>eH; f/, posterior lobes; 
ar, longitudinal fissure; y, 
y, fissure of Sylvius; /, 
the optic chiasm; z, cor- 
pora albicantia; (/, the 
Sons viUTilii; e, the ine- 
ulla oblongata; 7?, spi- 
nal cord ; ] , the olfactory 
bulbs and nerves; 2, the ^ 
optic ; 3, motor oculi ; 4, 
pathetic ; 5, tri-facial ; 0, 
external motor oculi; 7, 
portio dura and mollis; 
tt, pni'uuiugastric, glosso- 
I>liarvugea], aud spinal ac- 
cessory ; 0, hypoglossal. 

Many of tlie cranial 
nerves, as the optic, anse 
fojui distinct gauglia; we 
may thcrefoi-e regai-d the cerebrum as beiug couijiosed of a 
number of ganglia, which possess special functions. 

Tlic cLTcbelbuii consists of „. ,« 

par.illi'l phifes, and is covered 
l)y llii- lUfinbraiies of the bmin. 
From it columns of nervous 
substance pasn, to unite with / 
other similar columns fi-om the ' 
cerebruTii, fi) form tlitr medulla 
oMi>iignta, whli-h is oiriiieeted 
with idl l!ie great ganglia at 

tlie liase of the braiu, aud is The ccnteiium- 

the commencement of the sjiinal cord. 

The sjjiual coixl is placetl in the vertebral oilumn.and term- j 
inates below in the canal of the sacrum, by dividim; into i 
number of branchess called the canda e(|uina. The t^bape of ] 
the cord varies, as is shown in the fulhiwing figure, which rep- 
n-^ents seetions of difi'ereiit [H.rtious. On examining such seo i 
tiims, we find thiit the bulk t-f tlie spinal cord is composed of 
white nervous sulistaiiee. Jirrani:ed in six mlumns, an anterior, 



Whi.1 Ik 111" ,'»in[«*irl"n .pfH"- .■.■ivl 
wivbnimT Whm 1" iIip m^'lnlln "''I" 
while iiibXnnco of the curJ arrniigcd 1 



i^ninr U(t.,i i, 



TIIE SPINAL COKD AND SEIiVES. 



135 




I 



• • 



middle, and posterior col- 
umn on eacJi side. Tliese 
inclose a certain portion 
of gray substance, which 
wcupies the central i-e- 
gions of the cord. The 
j)ro]K)i-ti()n of gray mate- 
rial varies, as is shown iu 
the sections in J^iff. 127. 

Exteriorly the spinal 
cord is covered by a series 
of menilji-anes similar to 
those of the brain, and of 
which they may lie re- 
iraRle<l as continuations, 
rile first membrane is 
composed of the blood- 
vessels which nourish the 
or<,'aii; the second nttbrds 
protection ; anil the third 
IS analogous to the dura 
mater. From the anterior and posterior columns of the coi'd 
the nerves of the body take their origin; they are all foi-med 
of white nervous substance, and convey impressions to and 
from the nervous centres or ganglia. 

The nerves of the head are derived directly fttim the base 
of the brain. Many of them are engaged in special funitinns. 
as the oj)tie, olfactorj', and auditory, while others are distrili- 
Tited to the muscles and skin of this legion. The nerve wliicli 
supplies the facial muscles is called the facial; it passes over 
the masseter muscle, and is the chief nerve of expression, as is 
demonstrated by the blank, expresaionless ai)pearance of one 
ide of the face when the fiicial neyye of that side is injured. 

The nerves of the trunk, iijiper and lower extremities, are de- 
lived from the spinal cord. They originate in the anterior 
and posterior coluums of the conl, and pas.s out through fbram. 
ina lietween the vertebne. In ^iff. 128, a is th« cervical ptir- 
tion, with its nerves; J, the dorsal poition and nerves; c, the 
lumitar portion and nen'es; f,tlie pons varolii. 

In the neck the first four sjiinal nerves unite soon after 
emerging from the vertebral column, and foi-m a plexus, fi-om 




136 



THE SPISAL COUD AND NERVES. 



which hmnches are given to the nius- 
I'lfs (itiout the shoulder. The iv- 
iiiniiiing f'mir cervical and fii-st dor- 
i-al form the Itraohial plexus, fmm 
which the axillary, median, radial, 
iiiul ulnar nei-ves are derived, and, 
jiassingdown the arm in the vicinity 
■ if the arteries, are distributed to the 
inusifh's (jf tlie upper extremity. 

Tl]<i ilui-Mil Spinal ner^"espusa uitli 
tlic iiitLi*Li>st:d aileries iu the groovt. 
in till- under edge of the rib. Tlit 
saiTiil nerves unite to fomi the greit 
sacnd pli'xuH, froiu which the largest 
uerves in the body, called the scmtii 
or ischiatic, are detived. They pa^-i 
down the legs, giving bmiiches t 
the nmseles of the lower cxti^cmiti 
and accompanying the arteiies 
their course, and bearing the sit 
uamea In addition to tlie nci 
and -J)lexu8ea mentioned there 
many otheiN, bnt we niuat refer t! 
reiider to the worka on anatom} ki 
their descnption. 



LECTURE XXVIII. 

ACTION OF NKKV0U8 SYSTEM. 




Fiiucthn nfllir. whitn •^i/fm/iiiice. — liapt btj 
of (!,.■ Pi.nv. >,,„„;• of r,ni.,;'^ghr.».— S 

',.!.' (h<„:,ii...-i:.:ji.i., ■!,.:, <;,in;,na.~i 

i;u„.i „i-f/,r ^Wr'-^. Sj.i,i'il Vo,-(f.<i,n f/li i 

,tt t/i<i ii'tse oft/ie Brain, (iiiil ••fiUt < rr- 

tbmm fit emh ot/ter.~f'.'iii.-tioiis of tht Th-Bplm. lohL 

VmbAliim. —Review o/t/tc J-Wnclioii» of the Difsutons of the ^trvoui 

Having described, as far aa our limited space permits, the 
anatomy of the nervoun system, we next ])asM to the explana- 



r 



rrjJtTIONS OF TIIK (SiJAY AND WHITE Sl'BSTANCE, 



tion of tlie functions of the tlitfeient parts, as far as they are 
uiiderstotid. 

It is tho province of the ivhite matter to coiuluot the tienous 
force, as is clearly demonstrated by the fact that if we fiit a 
nerve all power of motion and sensation ar« lo^t in the jmrts 
supplied by it ; but if to the lower cut extremity of the iieixe 
ail electric current is properly applied, movements are produced 
in the musclea supplied by the nerve, ivbile, if the upjier cut 
extremity is irritated, pain is felt, which is refeired to the Pame 
musclea or regions. The r.ite of transmission of iniprei^sious 
along the fibres beai-s a direct ratio to the temperature of the 
animal. Iii maij it is ,ahmij ^ j'f _ ^ijl ,it.^C £Qnd.. 

In a siimlarnuilimTjwem tliejfjjji^ 

m atter op^l'inates t)i(j tt / yce. fur if the gray substance of tlie gan- 
glia is destroyed, tlie ]»nver oi' originating motion is lost, though 
the nerves ^rlll retain their mmhii'ling power unimpaired, aa 
may be shown by testing them with the electric cuirent. 

Tlie ganglia, as lias Tjeen stated, are composed of gi'ay sub- 
stance. They not only originate the nei'vous force, but, under 
certain circumstances, they also become the lepositories of ev- 
ery s]iecies of nervoti.s manifestation. In such registeiiiig gan- 
glia thoughts and impressions are stored away, the previous ex- 
istence of which is almost forgotten, until by some incident 
they are recalled in all their pristine vigor ana clearness. 

In the adjoining figure, the i-elation of the 
"^' '"■ registering ganglion to the simple ganglion is 

shown; a and e are the poles or nerves con- 
veying impressions to and from the simple gan- 
glion, V, wdiich is connected by another nerve, 
c, to the i-egistering ganglion, r. The impres- ^ 

sion liroiight to the ganglion v by the jj^jififli^^ 
nerve a is registered, or in part retained l)y . 

the ganglion 9\ which also holds in reserve a 
part of the foi-ce generated in v, and conveyed along the t-ffer- / 
ent nerve e to produce motion in the parts to which a and e 
are distributed. 

The fibres \vhich form a uerve are engaged in two distinct 
actions : some, like a, are afferent, and convey the _ impressions 
to the ganglion, while otliera. like e, are efleren t. auu convey 

tlow is it protof! tlint Iho nti'vcn convey im|iies!ion!i? Wljni U llie inpidiTV of cimvi'v- 
nnco of impressions nlong tlie iicncs in miin f Wlinl drlenninee llie mm uf conrcjnnte ? 
Whni i« tin? duty of iliccriiy niiuiiir? Wlinuro TeKi"'criiig cnnBlia ? Whiii ialho rDlatiiin 
of iho regihlei'ing lo ilic &im|ilc gnnijUn? Uo ull the Sbrea ofn nenc col " 
tbe same dirocllun ? 




138 



BEGISTEKISG A5D INFLUENTIAI. OANQUA. 



the motor force tn the ijiiiisfles. When we irritate the sole of 
the toot of a f)ei"soii who is sleeping, tlie iiiij)ression is conveyed 
along the aft'ereut fibres of the nerve to the spinal cortl, and 
tlmmgli the ett'erent fibres the nervous foi-ee ia sent wbidi is lo 
produt-'e luoveiuetit in the muscles attached to the irritatetl 
member. Such motions ocriir without tlie knowledire of the 
individual, and may be pro(lin.'i'd in ;iiiiimils in which the spi- 
nal cord is cnt ; they tyre thcrct'cjiy c;illfd reflex actin 

It has been stated in a previous jmnigraph that the spinal 
cord takes its origin in certain ganglia iit the base of the bmiii. 
The relations of these to the cord and nerves are sindlar to 
those shown in Fiij. 120. The nerves are the jmles a and 
the spinal eoii.1 is the simple ganglion v, and the ganglia at the 
base of the brain repi-esent the registering ganglion, 

In the diagram, riff. 130, a more perfect devel- 
opment is illustrated. The registering ganglion 
is divided so that one jwrtion, *, takes charge of 
the sensations, while a second, w, superintends the 
motions to be produced. Another element has 
also apj>eared, the influential ganglion, e c, as it is 
called, which is represented in man by the cere- 
brum. 

Upon the size and development of the cere- 
brum the position of the individual in the scale '■'""™"^'^ 
of iuti'ltcct di'pi'n<ls, the anterior lobes seeming to be the spe- 
cial seat of intellectual power. Mere bulk is not the only ele- 
ment of size in the cerebrum, for we must also consider the ex- 
tent of gray matter exposed to the action of blood-vessels, 
cerebrum which has deep fissures between its convolutiiina 
iKWHesscs more power than another which has greater bulk 
but shallow fissures. 

In the works on phrenology the cerebellum is supposed to 
be the seat of the se.vual passions, 1 mt this is not the case, for 
a laiij^ part of the organ may be destroyed mthout injury to 
the proci-eative jxiwer. The true function of the cert-belluni is 
to co-ordinate the forces Avhii'h have been created in the gan- 
glia of the brain, ami ]irnducc n';.^riilarlty in the action of nm.* 
tdes which are to execute reipiiri-d movements. That this is 
the true explanation of its function has been demonstrated in 

I>c3cril>c iliP Bftion of the sffisrnii and the pfffrrni fibres^ Wlml nra refli 
Wh«l i* the Tolslinn of iho opinni curd tn lliv B»"Bli>« ■! Iho t«M of ihe brnin 

IliP intluirnlial ganglion? Wlml i" llio rclniimi of ilie cerebrum lu the Runs''" - 

of tliobnin andilie coM? WhntiktenninM ilio inictliviuiit poirci? Ii (be ecrebcUaiD tbt 
KM of wxual paision ? Whai ii ihc dui; of ihc Mrebdlum f 




r 



REVIEW OF TOE NERVOUS STSTEJIf. 



tlip most satlsfjictorj' maiiuer by j;jygeijtimjgjj]i_jmjjjj^ in 
ivlik'li all attempts at motion in a straiglit Hue are destroyed 
by iujuriug certain parts of the cerebellum. An animal so 
treated can only move in a curved or circular coui-se, aiid no 
longer possesses the power of co-ordinating the action of its 
muscles. 

In order that there may be no obscuiity regarding the func- 
tions of the different parts of the nervous system, we restate 
them in a condensed fonn. 

The sympathetic system regulates the processes of organic 
or vegetative life. 

The cerebro-s])inal axis presides over the manifestations of 
animal life 

The nervea are the channels of communication between the 
ganglia, and organs, and tissues, conveying sensation and action. 

1 he sjiinal cord is a simple ganglion, and can oiiginate mere 
reflex actions. 

The ganglia at the base of the brain are the registering gan- 
glia, which also pos-sess the power of oiiginatint; nervous force. 

The cerebrum is the iinal registering and influential gan- 
glion. 

The cerebellum is the co-ordinating ganglion. It is the bind- 
ing-i-oom of the printing-house of the brain, in which the ])late8 
and jiiigesi timt have been formed in the engra\'ei's', composi- 
tors', aiul jM-css rooms, or ganglia of the establishment, are 
I'lacid in proper relation to eacli other, so as to form a tiook, 
which may be I>oxed up with other worLs taken from the re- 
pository or cerebnun, and sent down the dumli-waitcr or ."pi- 
nal eonl to fill an order I'eceived through the teleg;rapli or at- 
ferent nerve by the railroad or efferent nyn-e, > ^> 7 ' 'i Th )j { 

How 11 iho funnion uf the curebcUum dcmonslrntcd ? What is ilic fun ctioiM^^n « m- 
pathelic ncrtc— of ilic cercbro-'pinnl system — of tlic ncrvps— of ihc »y\na\ coni? ^Tnui is 
"la duty oftlie gnnglia nt the bnse of the bruin — of ihf ccrtbrum — of thu cctcbcllDin ? 



DISTlilBCnON OF NEUVES TO lilK SKIN. 



LECTURE XXIX. 

THE SPECIAL SENSES. 

The Five Senses.— TTie Sense of Touch.— Its Location.— The Skin de- 
scribed. — 77te PapiUm. — Acuteneas of Sefiaatiott d^aida on ike nunib^ 
of PapiU<e. — Sense of Touch corrects tliat of Vision. — Svnsf of Touch 
and of Tenijterature are distinct. — Localization of Touch in Loteef Ani- 
mal''. 

The Special senses by means of which man is brought in 
communication ■with the external world are five in uiunber — 
Touch, Taste, Smell, nearing,Vision; of these, the senses of 
touch, taflte. an J siiiell act by direct contact . Tlie first is foimd 
in the lowest furm« of animalw ; it is tne simplest In its con- 
struction and method of action; we shall therefore first exam- 
ine into the anatomy and physiolojrv of touch. 

This sense is situated chiefly in the skin, which is composed 
of two layers; the extei-ior is called the cuticle, and is formed 
of ej>ithelial cells, which arise from the lowest portion of the 
layer, and gradually become thinner as they are more exterior, 
until finally they become scale-like, and are rubbed off by con- 
tact with vaiious substances. 

The function of the cuticle is to protect the parts IjHng be- 
neath it. In man and the majority of aniuials it is pnitected 
against the action of the air, and kept soft and flexible by a 
peculiar oil secreted by special glands; in fishes and creatures 
wliich live in the water it is covered by a thick mucilaginous 
inat*'ii;d which answei-s the same purpose. 

When the cuticle is subjected to continual pressure it be- 
comes gradually thickened, as, for example, on the soles of the 
feet, where it i-eaches _ a thickness of an eightli of an inch. 
Sometimes the induration is verj- small in extent and circnm- 
scribed, forming corns, which pi-oduce severe pain, not onlv 
from their own sensitiveness, but by pressing on the uen'es oif 
the cutis vera. 

The cutis vera, tnie skin, or denna, is freely supplied \ritli 

Nnmc iho upccinl wnw*. Which npiidcn net bv dirpcl cnninci ? Which is rh~ rimi4nl 
n-nycJ DcscrihcihoexicmnUByprofiho »tiii. Wh«isi1it fiinctiun ofihc cai>r'lo7 Hint 
i* ihc ekin cnnbl«l (o rotnin in Boftncn nnJ Bcxibitit; 7 Whni nrc corus ? Wtuit ramv 
•n giren to tho kcowI Itftr of the ifcin ? 



SIZE AND SHAPE OF THE PAPILL-E. 141 

nerves, which terminate in a loop covered by cuticle, fomiing a 
pixyection called a papilla. The papillse are scattered all over 
the budy, but are verj' numerous iu the fingei-s, which are in 
man the sj>ecial organs of touch; on thera the papilla are ar- 
niiiijed in rows, which cover the anterior surfkce of the hand 
and fingers. 

The pflpillie which foi-m the ridges of the tips of the finders 
are about xsoth of an inch in diameter, and xJ^th of an inch in 
height. In form they are conical, as is shown in the following 
figures. 




Fig. 13!. 

filial 



The greater the number of papilla? in any pai-t, the greater 
is its sensitiveness, as is demonstrated by liringing the points 
of a pair of compasses in contact with the skin of varions parts 
of the liody, when we find that in those parts where the papil- 
Ue e^ist ui greatest numbers l)oth the jjoints of the coni])as8 
can be distinguished distinctly when separated by the smallest 
interval. By means of the same device we can readily determ- 
ine the region of greatest sensitiveness; on the tip of the 
tongue the jxiints cease to be distinct, and merge into one, when 
the interval is reduced t<:> -^th of an inch ; on the tip of the 
finger the same result is produced when it is ^^th ; on the lips, 
^tli ; <tn the tip of the great toe, A an iuch ; and the middle of 
the thigh, 2i inches. 

/"By means of the papilla two distinct orders of irapreasionsN 
^re aiipreciated : 1st. Premtn'e, which acts mechanically ; and, | 
2d. Ti'mperature, which acts chemically, by producing vanation / 
^n the rate of waste and nutrition. ' 

Through pressure or contact with various objects the sense 
of touch becfomes of great importance to the superior sense of 
vision, for the latter is to a certain degree educated by the for- 
mer l)etbre it reaches perfection. The eye can of itself determ- 



Whnl lire iha pnpillw ? Wiii.i \« t 
Hoff [Iocs the numlx^r of pn|iill[c oRcrt I lie » 
scnsit ire Hess orTarioDi pnris of the bod}*, llow do pi 
piUc? 



c tlicj' nrrnngcd on the iin|:«rt>7 
' any ]jnrt ? Nnmc the unlcr of 
V and [cnpcniiiini ntFi-ci iho pa- 



142 



DECEPTION OF THE SEN8E OP TOCCH. 



ine tlie crude outline of an object, but it cnn not appreciate eo- 
■ Vulity until it has fii-st been educated by the sense of toiicb. 
This fact was demonstrated satisfactorily by the ease of Franz, 
in wliich an operation for congenital cataract was pei-fonnefi oa 
the patient after he had received the information usually im- 
parted to the blind. The operation was successful, and tht- [«• 
tient obtained a very fail- degi'ee of vision. On presenting in 
hiui a cube, he thought it was a square ; a sphere and a ili«! 
both appeared to bt- circles. When the objects were jilaeeii in 
^Iiia hands he ininiediiiti'ly recognized their true figure, and was 
ksunirised at his ^stujildity iu committing such envrs. 

Under certain conditions the sense of touch is siugularlvdi 
eeived, as, for example, in the experiment of Aristotle, iu whicli 
a pea or other small sphere is rolled under the ti]i of the indi 
and middle lingers. So long as the fingere ai'e in their natural 
position, the individual has no difficulty in stating under whiHi 
Auger-tip the pea is, but ^vhen the fiugei's are crosseil over each 
other, there is often the greatest uncei-tainty in the mind of thu 
expennienter regarding the jwsition of the pea. 

If we pass the tip of one finger over any sui-face, we 
readily diseover whether it is flat, convex, or concave ; but if 
iinotlu'i- i)ei'son takes hold of the finger, and passes it over the 
Bui-fiicc, he may deceive us completely regjufling its nature. If 
the surface is flat, and he presses the finger more when passing 
over the centre than at the circumference, he will induce us to 
think that it is concave ; by pressing less at the centre, it will 
be made to appear convex, 
r Sometimes sensations whicli onginate in the brain are refer- 
/red to the skin of various parts of the body ; these are odeu 
I very disagreeable and annoying, being likened by the suflFen* 
I to the crawling of ants, or some such uiioomfoi-table iiaprea 
Vsion. 

The sense of temperature is distinct from that of contact, at 
true touch, as is demonstrated by the fact that in ])nralvsis thi 
fii'st is often destroyed, while the second remains; and the HD 
fortunate individual, having lost the appreciation of the vicinity 
of hot substances, is sooner or later severely burnt. 

In appreciating temperature, the skin acts more like a call 
rimeter than a thermometer, measuring the quantity as well i 



Haw (iocs tho BOnsc urtourh p 
ivhnt circiimatnnccs mny ilic sens 
ptn of toiicli oriRinnle in ihc hni 
that of [cmporalurc nrc dulinct i 



TTTCt llml of Tuion ? liciMc il 
nf much bo dcceired? fnii s. 
I ? How is it dcmonslrni^ ' ■ ' 
Does the skin tncuuic t' 



alT..i-[iiig il 




THE TONCrE DESCRIBED. 



U3 



the intensity of the heat to which it is exposed. Of this any 
one limy satisfy himself by placing his finn;er in a ^■esseI of hot 
water, and tlieii iniinersing the whole haud. Tlie intensity of 
the heat seems in the latter instance to he far greater, yet we 
know that it is the same in lioth cases. Appreeiution of tem- 
perature Ity the skin is therefore very nncertam, unless we take 
mto account the extent of surface exposed. 

In many animals the sense of touch is specially developed in 
some part of the body. In the hog it is m the snout; m the 
cle pliant, in tlie trunk; in insects it is in the niitennie, or feel- 
ers, which often act as organs of hearing. 



LECTURE XXX. 



Thames eomposinff the Tovgm. — Sefimttotia appreeiated by it. — The Pet- 
pitlce deacnhed. — Distribution of the Senaee of 'J'vuvh and 7'a»te «n the Or- 
j/an. — Action of the PapilltB under the Injlnmee of »troti{f Plm-urx. — 
Deception of the Organ of TaHe.—Zocat/on of the Heine vfSmell.—Di- 
viiiona of the Jfamd CuBity. — Dtatri/nition of the Olfactory A'eree. — 
Condittotis es*e7itial to tlte proper Action of the Sense of Hmeii. — Inverse 
or subjective iSensatione. 

Tim sense of taste is placed in the hnccal cavity, and is situ- 
ated in the tongue, and not in the palate. 

The tongue is composed of niiiscles, which aix- covered by 
mucous memlirane, and treely supplied with blood-veseelN and 
nerves ; it is consequently capable of a great variety of move- 
ments, assisting in the production of certain sounds called liu- 
guals, and by its sensitivenesB enabling us to select those arti- 
cles (if food which ai-e suited to the ^\'ant8 of the system. 

The tongue is capable of three distinct classes of sensation, 
viz., touch, tenij^erature, and taste. The first and second are 
most acute at the tip, and gi-adually fade away toward the 
base, while the sense of taste is dull at the tip, and acute at the 
base of the oi'gan. 

The papillic of the tongue are of two classes, some being 
small and others large. The first ai'e most numerous at the tip, 
and are the papilla; of touch, while the large papiUse, in which 



MciKion ihe cporini lurntiou of ihc si-nsc of I 
!*■ ilie wnsi: of ln«lc InctHi-il ? W'hnt tiiaurs col 
^iiiona iip|<rcciiiicd b* tlio lonciic ? How nrc ih 
loneuc? D*»cribe tKu pngiillic ofilio loDBiie. 



jmt of iliD liiwvr nnimnls. Wlicra 
loijpue ? Wlmi nrc ilie three stn- 
r tonch nnd tiwie dlsiribiiied on the 



T 



ACTION OF TirE PAPILL.E OF TIIK TOycrE. 



I 



tbe gustatory nerve, or nerve of taste, com- 

;; nicnces, are found at the base of the oi'gmi 

^- in the gi-eatest uumbers, 

%. ;jU In order that any substance Rh.nll affect 

i /the sense of taste, it must be solulile in sal- 

^ / iva; all bodies insoluble in that fluid mv 
' / tasteless. Salt, by increasing the wihibilily 
of vanous materials, rendei-s them iiiurc 
gratifying to the palate; it is tlH-ivfnrr 
highly ])rized aa acondiment, togetlur with 
many other artioles, as pepper, mustard, etc. 
Under the influence of strong flavors like 
vinegar, the ])apina> change their figure, be- 
coming elongated and pointed ; it is there- 
fore probable that the sensation of taste '^*'" '^""^^ 
may I»e jjroduced by the tension to which the nerves are sut- 
jected. 

The sense of taste is intimately connected with that of smell, 
as is demonstrated by the fact that many substances lose their 
taste when the nostrils ai'e closed ; but this is by no means 
the case always, for there are many articles, like quinine, which 
aft'ect the sense of taste jK)werfully, but are without any action 
on that of smell. 

As the sense of touch may at times be subjected to decep- 
tion, so that of taste may also l>e easily deceived. A tunart, 
quick blow delivered on the tongue gives the impression of a 
strong flavor; an electric current produces a metallic taste; 
and a jet of air thromi on the tongue gives a sensatiim similar 
to that produced by saltpetre. Impressions which originate in 
ft disordered condition of the brain will also produce impres- 
sions similar to those caused by fiavor,s, being sometimes pleas- 
ant, l»ut usually disagreeable. 

Temperature possesses considerable influence over taste. A 
very hot or a very cold liquid taken into the mouth seems to 
aft'ect the papilla; sn profoundly that some few seconda must 
elapse before they regain tlieir power. 

SMKLI.. 
The sense of smell is situated in the nasal cant)', which is 



\v 

Univ 

tbott 



rondihoii is r»spnli»l in onlcr lli«t « cnbfilHrnv »houM nflect (Iib oriMti of tutef 
CK uilt nffcct Ilia fliiriir or nnirtra of food? Ilnw do iirong Sbtoii like vinrinit af- 
pnpillier Hops the snino gnhtUiiio; nU'iiys nff«:l llie oi^n of tasia nnd that of 
'II? Whnl imprcwtioni mny (Icceivo ilio nn» of iiutc? How doe« lempcniato aflict 
of laale } Where ia ihv scaao of •mell liinucd T 



TlIE SENSE OF SMELL. 



145 




divuled by the vomer into two lateral 
portions, facli of wliicli in subdivided 
by the turbinati'd Imnfs into a eiipe- 
rior, middle, and Infi-rior nn-atus. The 
sides of the ciivity.aiid tlie tliiii,,scroU- 
j— like plates of the turbinated bones, are 
J^ eovered by mucous niemhrane, called 
'" the Schueideriau membrane. To it 
the nerve of smell, or olfactory, is dis- 
tributed, the greatest portion of the 
netTe passiug to the upper 
meatus, so that when the oaor 
i« feel>le or delicate, the air is 
drawn in strongly, to cany the 
, odoriferous ])ai1:iclea into the 
upjier part of the cavity. 

in order that sulistances 
shall affect the organ of smell, 
'■ they must be capable of as- 

suming either the vaporous condition, or such a fine degree 
of subdivision as to be readily drawn in by the currents ot air 
intii'diKfd during respiration. Tlie conveyance of odoriferous 
particles by currents of air jjrecludes the necessity of mobility 
in the organ of smell; it is therefore stationary iu nearly all 
animals. 

The senses of taste and smell are confined in their action 
when compai'ed with those of hearing and \ision. The eye 
can at a glance perceive a host of objects ; the ear can detect 
many sounds; but the sense of smell can apjireciate but one 
odor at once, failing to discover those which are feeble, if at 
the same time one ^vhich is powerful is present. 

The sjwcial function of the sense of smell is to enable ani- 
mals to discover the presence of substances suitable for food. 
Tlie carnivora, in whom the turbinated bones are wonderfully 
extended and intricate, affording a veiy large surface for the 
distrilmtion of the olfactory nerve, can discover the presence 
of food which is hidden from sight. The herbivora will, in 
pasturing, select out tlie tender lllades of grass, and avoid all 
offensive weeds, by the aid of this sense. 

In reptiles it is developed to a ver}' slight extent; in bii-ds 

Whoi nrc tlio divlsiong of iliD nosiil cnriij? Give the iinmc orilip mnuoua membrane nf 
■ lie nnsnl rHriit-, What » iho namo nf the nerve orxmi^ll ? Tu nhEcli mrnliis is it chipll; 
diairihuleii ? Whnt condition ia CHenlial in ordpr Ihnt subslnnces ehoulul afftcl lEiu orgari of 
■mell? What li tba ohjcct vfthc KiiworimcU? 



146 ISrV-ERSE OR srBJEfTIVE IMPRESSIOXA 

it is more perfect; hut even the carnivorous Tnrda do not (lf|wuii 
upon it to discover their food, as was shown by Audubon, who 
stuffed the skin of a donkey >vith straw, and hid tlie can-ass uf 
the animal under leaves m a ditch in the vicinity, when he 
tbiind that the huzzurdsf quickly discovei-etl the iaufled skin, 
but failed to find the highly-odonferous caivass. 

The sense of smell is developed to the highest degi-ee in the 
carnivora, but yet there are peculiarities connected with it 
which are ver>- singular. A dog, that can without difticultj 
discover his master in a dense crowd, or follow him for a great 
distance by the odor of his footsteps, seems to take no notie? 
of the pertume evolved by a rose, while any of the berbivora 
would perceive it instantly. 

Among the numerous substances which the fashionable peo- 
ple of all nations have adopted as luxunes, none are more ex- 
traordinary than those employed as perfiuues. Ladies are dis- 
gusted by the man who indulges in chewing tobacco; hut 
what is to be said of the apj)ai'ent]y delicate, refined woman, 
who rendei-s her presence insufferable by the use on her jwrson 
of fashionable perfumes, derived from intestinal or other secre- 
tions of certain animals i 

As was the case with the senses of touch and taste, so the 
sense of smell may annoy an individual with odors which have 
no i-eal existence, but are iuiaginary, being the iiroduct of ]m 
own disoi'dered nen'ous system. To these jdienomena the des- 
ignation of inverse or subjective sensations ai-e given, and we 
shall find that they exist in connection with the senses of hea^ 
ing and vision as well as with touch, taste, and smelL 



LECTURE XXXL 

PEOPERTIES OP SOUND. 



General Prnperties of Waves. — Re/lection and Tnifrference of Waves.-— 

Nature of' JSouml. — Analogy of Sound Waves to Waler Waare. A» 

tion of the Ear Trumpet. — Velocity of the Pannuye of .Simnd in variom 
Me(fia.~-Effecl of Variation ofDeimtij of Air on Velocitj/ of .SounJ. 
— yon-conducting Pomer of Inelaelic iioaie«.--T?ie Pitch ana Quality 
of Notes. 

The ear is the organ of time, and determines the rapidity 
with which sounds succeed each other. It is vei^- complex ill 



'be 

■lit 

a 
th 



PKOPEETIES OP WAVES. 147 

:8 coDBtniction, and, in order to appreciate the functions of its 
lifFerent parts, we must first devotw some space to the consid- 
Wation of the nature and properties of sound. 

If a stone is east into perfectly calm water, a npple origin 
ates fi-om the point at which it strikes the fluid, and is propa- 
gated in a senes of concentric waves to the edges of the vessel 
containing the liquid. 

The waves thus produced ou water are measured in two 

ways: first, from the crest of one wave to the crest of the next, 

the distance lieJng called the wave length; second, from the 

bottom of the depression to a horizontal line connecting the 

rests : this measurement is called tlie wave height. 

When the waves reach the walls of the vessel containing the 
liquid they are not lost, but, being reflected backward, produce 
a I'eturn system of waves, ^vhich, if their crests correspond to 
the crests of the original system, produce a higher wave ; but 
if the crests of the second system eoiTespond to the depressions 
" the fii'st system, they neutralize or interfere with each other, 

id smooth water is the residt. 

As, in the foregoing instance, the vibration caused by the 
imi)act of the stone on the water is propagated through it in 
the form of ^vave9, so the rapid vibrations of a sonorous body 
are propagated through the air as waves of condensation and 
rela.'sation, which, entering the ear, produce the sensation of 
Bound. Tliey may be measured as waves on water are meas- 
ured, and their characters accurately determined. The phe- 
nomena of reflection and inteifereuce of water waves are also 
shown by waves of sound. If two systems of sound waves are 
80 aiTanged that the condensed part of one answers to the re- 
laxed of tbe other, they completely neutralize each other if their 
intensity is equal, silence being produced. 

Though waves of sound are analogous to water waves, they 

are by no means identical ; for while the latter pass along a 

single plane, and produce concentric circles of compression or 

elevation, the waves of sound are propagated along everj' coii- 

iivable plane, passing through the vibrating body as a centre, 

inning concentric spheres ot compression. 

Since waves of sound radiate from a central point of origin, 
ley gradually diminish in intensity as they occupy a greater 
lacel but when tliey fall on a ixjiicave surface, they are re- 

iiv mny wniTB Ic inengnreil? What U wme Ueighi? What is ware lencili? Can 
.js ho retlEcrcil? WJint in inefllit 1iy llie interference iif wnveR? What is uiind? Can 
_. wares of sonnci lio incninire<l? What is tho reanll of ihe interferenec of iwo svMemi of 
Mnd wBvcHf Wliai ix ihe difference bclwccn nuvcs of Bound and waTC» on water? 



148 



PHOPEETIE3 OF SOUHD. 



fleeted to its oeotral poiot or focus. This fact is taken advan- 
tage of in the constructioD of various instnunents, such aa the 
ear tnuopet, by which great naoibers of waves are coUci-ted 
and conveyed into the ear. and the ioteositv increased, thereby 
enabling a person who would otherwise \>e perfectly deaf l« 
hear iivith comparative ease. 

When wavt« of sound fall on dense media they are not lost, 
bat a portion is reflecteil. while the remainder is transmitted 
along the meiliuiii. Air, therefo re, is not abt-oliitely necessary 
to t he existenc e of sound : bat, since sounds almost always 
comWo us thi-ougn it, the various phenomena connected Avith 
them are always referred to air as the medium, unless it is otl^ 
erwise specified. 

The rate of transniission, or veloc-ity of sound, depends in a 
great measure ujM>n the density of the tnedinm through which 
It is passing; the other element of velocity is the elasticity of 
the medium. If wc notice a bricklayer working at a suitable 
distance, we remark that in cutting a Ijrick the sound seems to 
be produceii when the trt>wtfl is in the air, and not at the mo- 
ment of fstriking the brick; this is tine to the fact that a cer 
tain amount of^ime is retjuired for the sound to reach the po- 
sition in which we are atamliug. Another jjeculiarity whioh 
we can not avoid i-euiarking is, that instead of the sound Iwitig 
single, it is double. This U e.xiilained by the fact that in jiass- 
ing to the observers the sound has in part come through the 
ail', and in part along the wall and earth ; in the latter medium 
it movos with grealt-r rapitlitv than in the former. The sonnd 
which was originally single lias therefore become doubled by 
jiassing thixjugli two inetlia Avith difterent rates of velocity. 

The most recent ex|)eriments have shown that the velocity 
of sound in the air is 112.H feet per second : in water, 470o'; 
and, according to General U. L. Abbot, from 1240 to 8415 in 
earth. 

By producing variation in the density of any given medium, 
we can cause ttie rate of vdixity of sound in "it to van-. For 
e.\ample, atmosplieric air, if ^ul <yvted to compression, transmits 
sounds with greattT vcIdcIiv. and the intensity is ixHiuce<I in s 
less degree ; while if it is .■iulmiitted to a process of exhaustion, 



AVhat is the effect o( m 
act? Is «ir tho only mnli 

Tims the rdoeii; of ilie 




surfncM on vaiu of (oniul? How dots ihi* ear iruiiipet 
ithicli "Bves i<f tound mux be eiinirci*cd? Wliat cleierm* 
of wund ? Oire an iUoiiniion of ili'e iliererence of vctoc- 
nnd > ilentpT meiliuin. What it ibe vrKirit; of aoaml Ik 
the eQ'ect of inciOMinf nud diiniui>liiiix ilw Jcuiii; uf air oa 



iNTEXSrrr, pitch, qualitt. 



149 



rer 

El 



so as to reduce its density, the conducting power is steadily di- 
minished, until finally it 13 entirely lost, and we fail to hear a 
bell which h ringing violently in the air-pump jar when the 
density of the air is sufticiently reduced. 

Substances devoid of elasticity almost destroy sounds, for 
they neither transmit nor reflect them I'eadily, as any one may 
Hatisfy himself by attempting to speak in a room covered wth 
tai>estry. While the sides are Iiare they reflect soimds so that 
the voice can be heard without any difficulty, but as soon as 
the walls are draped ^vith cloth, the wa\'es, tailing on the soft, 
inelastic surface, are destroyed, and it becomes almost impossi- 
ble to hear the voice in the distant parts of the room, even 
when it is exerted to its utmost power. 

In addition to the properties already mentioned, sound pos- 
sesses three distinct characteristics; they are, 1st. Intensity or 
loudness; 2d, Pitch or note ; and, 3d. Quality. 

Tbe intensity of a sound Is determined l>y the condensation. 
Two sounds may Iiave the same wave length, but that which has 
the greater condensation has the greater intensity. 

The pitch is regulated by the wave length, or time of vibra- 
tion. The more rapid tlie viltrations, the shoi'ter is the wave 
length, and the higher the pitch of the note. 

By the quality of a note we mean to e.\press the difl'erences 
that exist in a note of any given pitch when it is produced by 
various instruments. Any one can tell wliether a given note 
is produced by a piano or a violin; in both instances the note 
is the same, and yet there is some difference by which we rec- 
ognize the instrument which produced it. 

Quality is partly the effect of feeble sounds which attend the 
niauner of producing the note ; cliiefly, it is due to the nature of 
the overtones accompanying the fundamental tone. These are dif- 
ferent iu diffi^rent sonorous bodies and also in the same body, ac- 
irding ,'ts different methods are employed to produce the sound. 

In addition to the pitch, intensity, and (piality of a sound, 

le ear also determines its direction. It is to be remembered 
that the course of a ."ound is represented by tbe radii of a 
sphere, of which the point of origin is the centre ; but it must 
not be forgotten that sounds are reflected by opposing sur- 
"" ;es, so that when a number of such surfaces are m proper re- 

■r element bcsiitcs density influenceg tbo raleof conduciion uf soiinil? Gire an 

iplc of itie fiiilnre ofinclnslic BubslnnprB (o conduct taund. What nrc llie ihrpc jirop- 

1 of fouiid ? How is tile inlPimity of adiind rpBalnled ? How is ihc piich nf n note 

palmed? Wlint ii> meant bj tho qiinlilj of a noic? Wlint ii ibc course of waves of 




laO EXTERNAL, MIDDLE, AMD INTERNAL EAR. 

lation to each otbtT, the sound cau be made to double around 
the fii'st surface, aud be readUy heard behind it. 



LECTURE XXXir. 



ANATOMY OP THE EAR. 



—FuTination of Wt 
■ Kar.- 



m 



Diviaiont of t/ie Mir.—Erternai E'lr iltserihed.- 
Tlie Ti/mpaiiic Canity ami Membrane. — Ttie Jionei qft/ie 
EuMachian Tube. — Ojieninga in the WaUa of the Tyuipanie Cavttjf.— 
Muacks of the Tympanio Cavity, — 77ie Pttrts of lh« Internal Ear — 
T/ieVealibiile liescribed. — The Memhrannus'ZfibyrtHth. — 77ig Ptrilyn'iih 
iiiii^ Enilo^'jfiiph .— lTifi. OtdiUis.— 'nie Sarvnte ami Utricl'^. — The .Scw^i- 
ciri^iflar CanaU . — TIte VocMea. — 77io L'imiua Spindis., JfniHoIua anil 
iSpiral Canal. — TVte Ilelicotrema. — IJittribution of the Atulitory Sent 
to the JnlentalJCai: 



The ear is divided into three paits for convenience of d*' 
seription. They ai'e called the external, middle, and internal 
ear. The external ear consists of the pinna and fv ik. 
auditory canal. The pinna is composed of carti- 
lage, which is eoveretl by skin, and thrown into 
curved folds, which direct the waves of sound 
into the auditory canal. 

The auditory canal conveys the ivaves to the 
middle ear; it is about one inch in h'ngfh, and is 
terminated below hy the tympanic iiicnibraue, or 
drum of the ear. It is sliglitly curved, with the 
concavity downward, find is lined 
with hairs jimt Lr!;iii<ls tliat secretf 
an acrid, oily materiid, wliifJi ]iif- 
vents insects enteriiiir thi- (npin. 
The seeix'tion of thesi' ixl.inds, when 
dried, forms the wax found in the 




I'iff. 138, a a, pinna and audi- 
toiT canal; f>, middle ear or tym- 
panic cavity; r, hammer and its 
muscles ; d, internal muscle ; c, an- 
terior muscle ; f, external muscle ; 
7, interior half of membraua tymi)ani; A, Eustachian tnbe; t,, 
mtemal ear or Inbvrinth. 




terminate ? Iloir ii tlit 



•r? Wluibdw 



THE OSeiCUB OB' THE TY'SfPANlO CA\^TT. 151 



I The middle ear or tympanic cavity is situated in tlie petrous 
art of the temporal bone : it is closed exteriorly by tue tym- 
panic membrane. It contains tLree small Ijones, and eonimu- 
nicates with the back part of the liuccal cavity, or pharj'nx. by 
means of the Eustachian tnlie. It is very irregular in its form, 
and U filled with air; in its bony walls there are a number of 
openings, viz., 1st. Meatus e.vterniis, or auditory canal, closed by 
tympanic membrane ; 2d. Tlie opening of the Eustachian tube ; 
3d. The fenestra ovale, and, 4th. Tlie fenestra rctunda, both 
of which communicate with the internal ear, and ai'e closed by 
niembranea; 5th. Tlie opening to the mastoid cells, which are 
lined by a continuation of the mucous membrane of the tym- 

Sanic cavity; 6th. The openings for tlie muscles aud their ten- 
ons. 

The small bones contained in the tympanic cavity are called 
the malleus or hammer, the stapes or stimip, and the incus or 
anvil, on account of the i^esemblance they bear to those imple- 
ments. They are connected together, tbnning a chain which 
extends aciuss the tympanic cavity from the 
membraua tympam to the fenestra ovale, the 
malleus, a, being attached to the tympanic 
membrane, and the stajies, y, to the fenestra 
ovale. To the handle of the malleus, near its 
root, the tensor tymjiani, i, the chief muscle 
of the ear, is attached ; the two laxator tym- 
pani muscles, c, (/, are also attached to the 
same bone, wliih- tlie stapedius, A, is inserted 
into the stapea By means of llicse iimsilfs the luembrana 
tympani can lie i-elaxed or stretched, and pressure jiroduced on 
the contents of the internal ear by the insertion of the stapes 
into the membrane of the fenesti'a ovale. 

The mucous membrane of the tympanic ca\-ity is veiy thin 
and highly vascular; it is continuous with the mucous mem- 
brane of the pharj'nx by the Eustachian tube, and covers the 
ossicles, tendons, and mu-icles contained in the cavity. 

The internal eai is talhd the labjnnth on account of the ir- 
regularity of the jiaits (.(imposing it It Lon'-ista of the voti- 
bule {a,o,i,Fig. 140). si nin in uhr ciml^ (a '1,0, Fig. 14(.'),and 

Wlieru is iho midille pari \\ lint n iniL u I s Ihu tympniiic cnvirj 

commanirnta wilh tlio plinnnx? AMni o\ unlli (if tlic lymiiimie 

CRTilj? WbnE Hre the niimcit uf tlio Ix iick i Id uhiit niomtirRiK! i« 

the miilleus ntinchGil? To wb'it memljrini I Wlint inuirlw are 

foolidinlhelympnnu! cnriti ? To w1int imrl 1 il 1 l r hor iTrnjiiili nlmchwl? 

Wiint IB ilio nelinn oF \\n.K! mi»i'l«s7 Dck ilu ilic iinipniiii. mu una niembranR. Whnl 
naina is Biren lo ilio inlcmnl inr ? Nnnic llio \wcl% Lomputing llio tiiLtj-nntii. 




TIEE VESTIBI'LE AKD SEJIICIKCULAK CANALS. 




cochlea (n, d, e. Fig. 140), which are 
holloweti out ill the petrous part of 
the teni|ioral Imne, and communicate 
externally "ith th« middle ear, and 
internally with the meatus internus, 
through which the anditoiy Der\'e 
jiasses. 

Tile vestibule 13 ovoid in fiijure, and "" """" ' " ■ ' 
the centre of conimuuieation of the other divisions of the inter 
nal ear; it is lined interiorly by a menilirane that containit s 
fluid' called the ])erilyniitli. In this tluid a sac-like body, calhtl 
the membranous labyrinth, is placed, which is not attached to 
the bony walls of the cavities, but id separateJ fixiin them by 
the penlympli. 

The membranous labyrinth contains the terminal tilamenta 
of the auditory nerve, and is filled ivitb fluid. The portion 
that occujiies the vestilnde w divided l>y a. central constriction, 
and caused to assume a dumb-bell sliajie. To one of the divi- 
sions the name of the saccule is given; the other is called the 
utricle ; fram it tube-like jirocesses ai-e given off, which occu]»y 
the cavity of the semiciifular cauals o,}>, <p The saccule and 
utricle each contain an otolith, or minute stone-like body, 
^ The semicircular canals are three in numl)er. They arc so 
'^iTaugetl as to oivnpy three planes at right angles to each oth- 
er, rc](n'wcntcd by the faces of a cube. They ai-e line*! by a 
meTubrnnc wlilili contains the perilymph, and m this liquid tha 
tube-like ]ii>rti'ins of the membranous labyrintli are 8Usjieude<l 
by the vessels which ]ijiss to tliein to couvey the retpiired nu- 
trition. The fluid contained in the nienibninous lab\-rinth i* 
almost identical in composition with the pe rilymph ; it is call- 
eil the endolymph. 



■ n.'wribo the miibiilo. Wlini in the perilvinpli ? DcKriho ihc mEinbnininn -«. 
Wlini nnniM nrc given lo ihc iliriaiom of ihe voiibulnr pnriion of ilie ropinbrannat. .. 
rinlli ? Wlinl nixMhi' otolilhn, nnil where nre they Tuuncl? Is llv mcnibninflus litbrrintb 

tfcciicii lolhe wnllnof ihccnriiicsin "liichit iiji'" '" - ■ " 
Whnt U (he otidolfinpEi ? 



xtWte Iho KDliciimlM c 



THE COCHLEA AND LAMINA .SPIIIAI.I.S. 153 

The cochlea i-esembles in its shape a common anaJl-ghell. It 
is composed of a central conical axis, called the iiiodiolu!', 
around which a conical tube, called the spiral canal, is wound 
^. j^ for two and a half turns. In the 

spiral canal ttiei-e is a thin wi)- 
tuni, called the lamina spiralis, 
which is comjxjsed of bone, mus- 
cle, and tendon, niul extends near- 
;v the whole !eii,trth of the canal, 
■lixi.linii; it into'lwn tuljen, the 
~<-,{lii n^tihiili, which cunuiunii- 
elites with the vcfetibule, and the 
xi'iihi I'liiipani. At the apex of 
the sjiiral canal the scalse commu- 
nicate with each other by an 
opening called the helicutrema. 

The fibro - serous membrane 
which lines the cochka is <'on(in- 
U0H8 with that of the vestiliulcs 
and seniiciiTular canals; it secretes the perilyni]>Ii, which is 
found in all parts of the internal ear. 

The portion of the auilitory nerve which is distributed to 
the cochlea passes up the modiolus, and the filaments cross the 




SeMlon nf Codiln. 




lamina spiralis, which is about one tenth of au inch wide at its 
base, and tenninates almost in a point at the helicotrenia. The 
filaments of the nerve are cousequently shorter and shorter to- 

Whui ia ihe »hn|x! of llie cy>cli1ca 7 What is ilic nnmo of the cotitml nxis of ilif coclilpn P 
Whni i» llic Rpiml cannl ? Wlint is llio Inminn tpiralia. nnil of whiil ii it ('umpii«.-cl 7 Wlmt 
' ~wn aciiliG, and what names nrc Riren to Ihrm ? Whni ia tbo hclirnircmn ? Wlinc 
tiire of llic membrnnc llinl nccreles ihe [KnlTitiph 7 Uow in Ihc audilory nerve di»- 
to the CDvhIcn 7 Are the filaments of the ncrro all of Ihe uimo length 7 



154 Fuscnoir of the pissjl 

ward the apex of the cochlea, and each corresponds to ij 
tout' liy its organ of Corti. 

Tbe internal, middle, and a part of the canal of tbe 
ear are contained in the pt- tious portion of the tenipoi 
which, iu the articulated sknll, lies at its base, so that tL^ 
perfectly protected. The dense, compact structure of this 
is very favorable to the conveyance of sounds, and they 
retained until they have been analyzed by the mechanisa 
the ear, when they ai-e destroyed by means of a specii 
trivance. 

The auditory nerve gains access to the internal ear 

openinir near tbe apes of the petrous bone, called the : 

auditoriua intenms, iu contradistinction to the opening at 
base by which the waves of sound are admitted. 



USD 

1 



LECTURE XXXUL 

HEABINO AKD TOICB. 



,^B 



I?ie Ekmenta of Sotatrt thaU «UA by the Ear. 
and Auilifoty Canal. — fmictiott of the Jftmbnma Tymj 
lions fi/the OiticUti. — Of the EattacAioH Tv&r. — l-^inrtioit oft/.- 
buU.— Ofthi Utinkircutaf Cauab.— Ofl/if Cf>rMfi.—The l>^dl> 
ofSounfUin tlte Internal Eur.— Dtr^^Hnttit of th< Ear. — Tht: Ji 
tin Loftvr AniinaU. — Voiet exittt in AirMtathimj AniataU, 
LarffHx dtambed. — VoetU Corde. — Character uf Song. — Of "^ 
— Of Juice or Speech. 

The ear deals with four elements of sound, viz^ DirectioSI 
teusitv, Pitch, and Quality. Tlie tirst is found by detemiin 
the rt-lative intensity of the ini]iressions produce*! on botb e 
the aflvantagc of a duplication of tbe oi^ns Ijeing \' 
may be advisetl of the existence of sounds on all sides, a 

tirei'iate their true nature without Wing obliged to tu] 
leail. 

The waves of sound which fall on the piuua are by 
cune*! surfaces dirwteil into the auditor)' canal ; the obje«i 
the pinuit, thcrt'fore. is to increase tbe numWv of waves 
Bouuvl which enter the i-aual b« acting as a reflector. 

At the Ixittoiu of the auditor)' canal sound waves cohh 
contact with the drum or tympanic membrane, the tension 

la nhil InBe MTC t]ie JDtenul »d RtiiUk «ar plkc«d* Hem >loo ■)>« •ndittn i 
rr.-irh Ibr inMnui] nr? Wiih wbat vlCiBMtB oftoxaid doM i)K ur <)*•]> Bos Mit 
rvriion of a sound ilewmiDtd? WluM »hMWfe is pua«d b; tbe 
What u ihc f KiKtm i-f tin fiaoh T 



rtojne 




r 



FfNcnON OF 'niE MEMBRANA TYMPANI, 155 

which can be varied by the action of the small iiuiscles insert- 
ed into the bones of the tympanic cavity. 

If the tension ou the membrana tynii)ani is increased by 
compressing the air in the tympanic cavity throutrh the Eusta- 
chian tube, sonuils become dull and obscured. When the op- 
eratioua of the muscles attached to the memlirane are inteifered 
with, sounds often become almost unendurable from their in- 
tensity. It is therefore supposed that it is the function of the 
tympanic memVtrane, or rather of the tensor tymjiani nni&cle, to 
nienifure the intensity of the sound conveyed to the interior of 
the oi^an by determiulug the force reijuired to produce the 
right amount of tension m the tympanic membrane. At the 
same time, the volume of eouud allowed to enter the ear ie also 
remilated. 

It was formerly supposed that the object of the chain of 
bones was to convey the sounds with gieater perfection to the 
internal ear; but the jointed nature of the a]iparatus entirely 
precludes this idea, for such a structure is liighly injurious to 
the ciiiiduction of sound. The tnie fuuctiou of the bones is to 
vary the tension of the niemlmma tympani by ii[)plyiiig in an 
advantageous manner the foi-ce jiroduced iu the contractions 
of the tensor tym]mni aud laxator muscles. 

The precision and praall amount of contraction of the mus- 
cles of the ear in their action on tlie drum is rivaled by those 
of the lar)n.x, the mn«;les of the vfjoal cords being able to pro- 
lUice a variation of one semitone by a coutraction cf jf^jijth 
uf all iudi. 

The object of the Eustachian tube is to give perfectly fi'ee 
communication with the external ail', an equality of pi-essure 
ou both sides of the membrana tjnipani seeming to be essen- 
tial to its proper action. Whenever the Eustachian tube 18 
closeil from any cause, as in sore throat, by the accumulation 
of mucus in tlie inHannnations tjf the mucous memlirane of the 
])lian'n.\,the sounds liecome nmtlled and indirtinct, and regain 
their cleai'uess «hen the tube is again freed from all obatnic- 
"tioiis. 

From the alxjve facts, we conclnde that it is the function of 
membrana tympani to determine the intensity or wave 
[E^Iit of sounds. 
[ There st ill remain two elements of sound to be ascertained 

pWhiU a ihe pfli'ct of ini'rcitMiig the {jrEsturo on llie lympnnic mcmbrinc ? Wlmt is ihe 
BCtlon of iho mombrmiB lymimni? Wlini is llie fimciion of tlic rlinin (ifboneg in ilio Ijro- 
»ic ciiTily? Wlini is i lie fmu'lion of llic EusUlcliiiiii Tube? IVhnl islbeeffect of temjio- 
T clusiiru of the Euiitiivliiuii lubu ? 






156 



DCTXRIIINATIOS OP PITCn AJTD QfAJJTT. 



by the interual ear, viz., Pitcli and Quality. It is to be 
lected that the vestibule is the entrance to tbe cocblpa an 
seraifiivular canals, but it pmbably has no special fiineticn hi 
yr)ii(l the conveyance of the soimd to those organs, the pi-ewne 
of the otoliths m the saceulus and utricle being accounted fo 
by supposing that they are rudimentary relics, like the man 
mse in niale-s. 

The f'uuction of the cochlea is to determine the pitch of th 
sound, as we shall endeavor to show by the consideration of it 
construction. 

It is a. well-known fact in acoustics, that if in the ^-icinitv ol 
any stringed instrument, as a piano, a note is sounded on soni 
other instrument, the corresponding string in the piano willh 
thrown into vibration, aud produce the same note. Ou tb 
lamina spiralis of the cochlea the auditory nerve is distrilmt*4 
so that each filament terminating in a fibre of Corti's organ di 
tects a given tinte. Wlien there is siniiiniity of structure, w 
may ^rgue siniilnvity of action. It is therefore pi-obable thati 
as the proper string of the piano vibrates in unison with thi 
note produced in its vicinity, so the proper fibiilla of the orgai 
of Corti is affected by the note falling upon it, and the innirea 
sion is conveyed to the brain. 

When a n(jte has piwducetl its proper effect in the cocblea i 
becomes necessary that it should be destroyed, or the ear avou1( 
he filled with the dying echoes of notes that are pas.sing away 
The final destruction of the note is accomplished by taking i 
vantage of the principle of interference. It has been stated...,^ 
describing the cochlea, that the lamina spiralis divided the sjn 
ral canal, so that two tubes, the scala vestilndi and scala tyi 
pani,were formed, which art" of une^jual lengths, and comnmi 
cate above through the helicoti-ema. In order to reach the i 
aments of the auditory nerve, the waves of sound must pass n 
the two scalie, and finally meet at the helicotreraa in such 
manner that the crest of one system of waves corresponds i 
the depression of the other, and they mutually destit>y etu 
other at\:er they have pntduced tlieir jimper impression. 

In aiidition to its formation, there are facts in the compan 
tive histoiy of the organ of hearing in the lower animals whic' 
confirm the opinion tliat the function of the cochlea is to di 
termine the pitch or wave length of sound. 

Wlini ii (he funciion of iho TestibnloT How h ihc [irtwncc ofiho otnliihs nfcoanli 
Tur? What ia the function at llic cochlcn? U|ion what prinoigjle dfws Ihe aclinn nftl 
coclilea dtppnd? Ilow is the forninliuo of echoes in tlio cochlea BTtndcd? Are ihc H 
*Cft1(D of equal lengths? 



r 



■niE EAR IN THE LOWER ANIMALS. 157 

The semicircular canals were formerly supposed to detenu- 
ir.e the direction in which a eound came to the ear, because 
they were placed in three differeut phuies at right angles, but 
it is also tliought that they detect the quality. This couclu- 
t*ion is dra\Mi i'rom facts in comparative anatomy, which t-how 
tliat the canals often exist in creatures which can detenuine the 
quality of a sound, but do not possess a cochlea. 

The simplest form of ear merely appreciates the existence of 
Pound ; it couslsts of a small sac, containing fluid, and an oto- 
lith. When the waves of sound fall on the aitparatus, the oto- 
lith is caused to vibrate, and, striking the wallii of the sac, irri- 
tates the ner\'e fibres distiibuted to them, and produces the 
impression of sound. By means of two such organs its direc- 
tion is determined. The next step in advance is the addition 
of a tympanum, for measuring the intensity; then the serai- 
cii'cular canals; and, finally, the cochlea, to ascertain the pitch 
and the quality. 

In its various stages of development, the eai' of the foetus 
shows a gradual advancement toward jieifection, similar to 
that we have detailed above, being at first like that of a fish, 
consisting of a sac and otolith, but finally reaching its perfect 
state. 

There ai-e some singular and interesting evidences amon^r the 
lower animals of adajitation of means to an end in the auditory 
!ippai-atus. In the predaceous creatm-e, the jiinna and meatus, 
or auditoiy canal, aie directed forward, so as to enable it to fol- 
low its prey, while in timitl animals they are dii-ected back- 
ward, so as to fa^■or escaiie dm-iug jiui'suit, BuiTowiug quad- 
rupetls are provided with membranous valves, to prevent dirt 
entering the canal during their subterranean operations. Many 
other interesting instances might be detailed, but we must re- 
fer the reader to the works on Natural History, and pass to the 
consideration of 

THE VOICE. 

Language is the direct means of communication with our fel- 
low-men. By it we make known to each nther our pleasures 
and sufi'erings, and exprc(-s the thoughts, ideas, and commands 
which control the destinies of men and nations; yet without 



Whni n-n9 fimnerlir «ii|ipose<l lo bo tlio fiini.-i 
prpsoni tlipory r«(:iirilinj[ ilio funni'in of ilic 
fiinn of cnr? Through wliul stiiecudcKw llio liutnan 
w>mc of llic jKCnliiuiries of Hie iiuiliiory D|)|iaralUB in thu luncr niiinialg. 




158 PBODCCnON OF soncDs. 

the sense of hearing it is useless ; we may therefore r^ni 
aa heing auxiliary to that sense. 

The power of proilueing a noise appertains to air-breiUhin 
animal^ creatures which are aquatic not being able to piixlta 
sounils by which tliey may hold communicatioo witli inhi 
members of their owu species. The voiceless state of aquat 
creatures is due to the fact that, since they do not [kw 
hings, there is no expii-ed air to employ for the piirjiose of pr 
ducing sounds. A few emit sounds liy special contrivances. 

In insects sounds are sometimes formed by the rajiid ru 
bing of homy snrface-s against 
each other; sometimes by the vi- 
bration of the wings, at in mus- 
quitoes ; in others by farcing the 
air fpfjiu the tmchea or air-tubes 
tfai-ough the valves of the sjiii-a 
cles which close the orifices of 
those organs : a rapid vibmtion 
of the valves is the eonseipience, 
and sounds are produced in the 
same manner as in the accor- 
deoii. 

In Ijirds there is a double lar- 
ynx, one being placed at the 
back part of tlic mouth, and the 
other at tlie liitiiix'ation of the trachea. The first is employi 
in the oi\linary act of respiration, and the second in the pi 
duction of song. 

In man theii* is hut one larj'nx, commonly known as tl 
Adam's apple. The vocal cords, /-. s, are extend- 
ed across its opening, o, which is protected above 
by the epiglottis, i. 

To the cords muscles are attached, by which 
they nmv be subjected to various degrees of ten- 
sion, ami the nature of the opening altere<l. By 
varying the tension of the cords, and the force 
with which the air is driven through the chink- 
like opening they inclose, vaiious notes are pro- 
duc*Ml. 

Song is the result of the vibration of the column of air 

Whoi cU» urnnininl) possMMu ilie power of uttering sonnds? 
Hiried lo fnr ilio |irmlHciion of loiiinl*? WhM ii ihc pcciil«riij' in iho Lu^ax of faj 
Urscribo iho lori-nx in mnn. What arc tin vocal cords? How An the atM jirodsa 
vinKiDg T 




NATURE Of ARTICfLATE SPEECH. 



159 



the larynx and trachea, hut speech is caused by the action of 
the tongue, lips, and muscles of the moutli. The simplest form 
of speech is the whisper; it is produced by fitrciug a current 
of nil' through the buccal cavity, while its parts are thrown 
into the pmper position for producing different words. In 
speaking the same movements are employed, but, in addition, a 
note is at the same time foi-med in the lai-j'nx, which is modi- 
fied as it passes through the mouth, and speech is the result. 

An ingenious experiment, fii"st advanced by M. Deleau, has 
demonstrated the above explanation of the natiu'e of speech in 
the moat satisfactory manner. It consists in passing an elastic 
tube thi-ough the uostrils to the back part of the mouth; 
thiough this another person blows gently, while the experi- 
menter throws the parts of the buccal cavity into the positions 



produciDg any ciren word, 
at the same time, tin 



for 



^Kcu] 



The result is a wJiisper, If, 
lie ex|)erimenter causes a pound to be pro- 
duced in his own larj'nx, theie is a double articulation, one as 
whisper, the other as audible speech, denionstrating that ar- 
ilate speech is pmduced by the mouth. 
Speech aud language are of great interest to the liistorian, 
for by tracing the roots of words of different tongues he can 
often discover the influence of a conquering on a conquered 
race, and determme the track through which a nation haa 
■jiassed in its career of conquest or of flight. 

^^pK«oms regarding Light. — ExinUnee, Nature, and Properties ofthfEthtr. 

^^F — -fi^ect of 7'emperatiirc oti the Intensity of Liyht.— Compovnd Nature 

^^ of Light.— Action ofPrianis. — Action of Hurfucen and Media on Light. 
— R^tection, and the Law which Governs it. — Cannes iiifiuendng the 
Jntensity of the refferled Ray. — IVanmxission. — Absor2)tio>'-. — Interfer- 

" ent^, — Interference aud Prismatic Spectra corinmivd. — Refraction de- 

tseriied. — Order of Refrangibitily of Colors. — lYieory of Coloration of 
Surfaces 
Vi 
Whn 



LECTURE XXXIV. 

NATURE AND PROPERTIES OF LIGHT. 



! Until quite recent times, the doctrine of Newton regarding 
ght was almost universally adopted, He taught that it was 
•oduced by the emission of exceedingly minute particles from 



Whal i» tlic diffiTcnct; bwwcci 
perinc "nd sp««ch? Describe t 
light? 



s iln'orj (if 



160 THE WAVE TIIEORT. 

the luminous ^ody, which, fulling on the retina, or senati' 
nervous coat of the eye, pi-oilucet! the sensation of light 

The emission theori/ of Newton has Wen finally set aside hi 
the H'fftv theory, which was perfected by the researchi-s of 
Young and Fi-esnel. It supiioses that the particles of the ti 
niinous body are in a state of i-ajiiil vibration, and produce in 
the ether waves, which, falling on the retina, give rise to tbfli 
sensiitioii of light. 

The ether, tlie existence of which is neoessarj' to the wavi 
theory, is supjtosed to lie an exceediugly attenuated mediuai 
which pervades all space, exists in the interior of transparen' 
Bubstaiices, extends among the planets, and fills the interstel 
lar spaces, The presence of such a medium is demonstrated bj 
the taut that comets and like eosmical bodies are subject to vi 
riations iu their times of passage through their orbitM, Thea 
changes in rate of movement are best explained by the I'etiiist 
ance ofi'ered by some medium like the ether. 

The marvelous rapidity (195,000 miles in a second) irit 
which light traverses space, as well as the manner of the movi 
nient, is ailiuirably illustrated in the following quotation : *'Mi 
tion ma>' be propagated and mutter aft'ected to a great di» 
tance without the ti'ansniis'»ion of matter itselC Imagine a 
straight tube filled with pens i-eaching fi-om London to York 
in a horizontal (wsition. If 1 force an additional i)ea iu at oue 
end of the tube, a pea will droji out of the tulte almost simul- 
tanei)usly. Now if the means by which this ^vas efl'ected were 
as imi)ereei>tible as the prop(w;ation of light, or of electricity 
transmitted tlirongh giK>d conduotoi-s, we should l»e astonisliea 
at the rnpiditv of the transit, and imagine that the identical 
pea put into tlie tube in London had arrived at York in an in- 
credilily short space of time; but, knowing the condition of 
the pmpusition, we peit-eive that motion may be 
thmughout a very long line almost instantaneously, without 
moving each particle (if matter far from its original position, or 
comiiniuicating to those particles much momentum." 

In 1S4(), Pi-ofessor J. W. Draper demoustrateil that all sdi^ 
l)odie3 Wcome luminous at the same temperature. The point 
at which such substances first bect)me visibly red-hot 19 97? 
Fahrenheit, and their brilliancy steadily increases with the ele- 
vation of temperature, so that at 2000° the light emitted is fo^ 

Whnt U (he w«\-i! ihrorj? Wmi i* tin 
ist? Al whnt lempcnit ulT do wtiilA luxxii 
aRbri ihD iniciuiiy of ilic light cmlllnl? 



COMPOUND NATURE OF LIGHT. 161 

' times as intense as at 1900°. Gases, on tie contrary, re- 
" ' \\ivv temperature than solids to render them vis- 
ibly red-Lot, as any one may satisfy himself Vjy holding a coil 
of platiniiin wire over the flame of a spirit lamp. The ascend- 
ing gas from the flame is not luminous, hut the moment the 
■wire is placed in it the temperatuiv is so high as to cause the 
platinum to emit light, thereby demonstratmg that solids re- 
quire a far lower temperature than gases to cause them to he- 
come luminous. 

Contraiy to what we should naturally expect, white or col- 
orless light is not simple, but compound, consisting of no less 
than ueven different varieties of colored lights. There are a 
number of experiments which show this fact, for which we are 
indebted to ^Newton, who found that if a ray of colorless sun- 
light is caused to fall on a i)rism (or column of glass whose sec- 
tion is triangular), it is immediately decomposed into seven col- 
oi-s, viz., red, orange, yellow, green, lilue, indigo, violet. 

Not only may white light be demonstrated by analysis to 
consist of seven coloi's, but we can by synthesis show the same 
fact; for if the beam of light, as it leaves the fii'st prisin,is caught 
on a second prism, equal to the first in all ieBj>ects, and placed 
with its ba.se parallel to the edge of the first prism, so that it 
may act in the opjiosite manner, it will recomblne the colored 
i-ays, and pi-oduce white light. 

The compound nature of white light may be shown in a 
le.ss perfect manner by mixing together in proper proportion 
powders of the colors of the si)ectrum, ^shen a white powder, 
of a slight grayish tint, is obtained. Another method of illus- 
trating the same fact is to paint the spectrum on a circular disc 
of pastel loard to which a rapid movement of rotation can he 
inipiutcd ; when the motion reache.'* a certain rate the colors 
become l)lended, and a light grayish tint in produced. 

The action of surfaces and media on light is to cause it to 
undergo reflection, transmission, absorption, interference, or re- 
fraction. 

1st. Reflection. — When a ray of light falls on a polished J 
surface, it is reflected or thrown back on the opposite side of a 
jierpendicular drawn to the surface at the point of impact of 

Do casra become luminoiia oi the snmc tempomiara na solids ? U Irj-lii limplt^ or com- 
|iiiiiiiil? Uow mnny colors iire found in wliito ligliif Whni is n prism? Name iho colort 
I'livliiccd liy iho Ai'iion of niJiism on white tiglit, Hmv may tliu compoiitid nainre ofliglit 
li'.- jiliciwii 1>y »YiillicsiBT ll'in niny iho compnuiid nntiire nrligltt lie illntHrulod by powdersF 
lliiw mny itic cciiiiixiBiiinii of iJplit bo ahotvu hy rlic revutring cord? Wliut is tliu awjon or 
siirfflcta nnd mwlinon liglil? What is reflcciion? 

L 



162 DISPOSAL OF KAYS BY fiUBFACES. 

the ray. The first is called the incident, and the second tlie 
fle;-teil ray. The ano;le between the incident ray and the pe^ 
pendieular is called tne anffle of iucideace, while tha^ t)etivw[i 
the peri>endicular an<l the leflected ray is called the angle of re- 
flection. The la\\' of reflection may be briefly stated as fallows; 

}V/t€n a ittif falh on any polisiml su Have it is rejiecUd, ani 
the angh of rejiecfimi is equal to the angh of inddenf^. 

The ani'onnt of light reflected depends on the intensity of 
the incident ray, the angle of incidence, and the nature of the- 
snrfaee, a polislied surface of pure silver possessing fer greater 
reflecting power than a similar siirtace of iron or other nietali 

TRANSstidsroN. — If a ray fialls on a transpai-ent medium, pncb 
as glass, a small proi^rtion is reflected by the surface, wliJe 
the remaining part is transmitted, or allowed to pass thniiif;li 
the medium. 

Absokption. — When light falls on rough, dark surfaces, it is 
absorbed, but not destroyeil, ft)r the surface converts it into 
some other force, as, foi- example, heat. Dui-ing the transiiii* 
Biou of a ray through a transparent medium a fjortion of the 
light is absorbed, so that, in addition to the loss by refiectioD 
from the surface, there is also loss by absorjitlon. 

Intekfeuence. — A ray of light inay be reflected in such » 
manner that the ware^ composing it interfere with each othiT, 
the crests of one system correspouding to the depressions of An- 
other, and producnig darkness. The ]>henomenon of iiiterfor 
ence may be illustratetl by causing a beam of light to fall on a 
very nari-ow slit, and then receiving the rays that pass through 
the slit on a screen in a dark room. The image formed is not 
a unitbrm spot of light, but consists of alternate light and dnrk 
lines ; the first being produce*! by the coincidence of crests of 
■waves, the seconil by the coincidence of crests and dejiresaous. 

If a ray is allowed to fall on a ruled surface of steel, glas*, or 
any other suitable substance, the reflected light is decompoM^ 
by interference, and a ninnber of spectra pnxluced. The spi^ 
truni of iuterfeivnce contains the same colors as the jmsniatic 
spectrnm, but there is a slight diffci-ence in their ]x>sition; the 
order of the coloi-s is the sjune in lHith, but in the intirferi'm* 
spcctmm the yellow is in the nuddle, while in the prienistic 

Whii are tlie IncMent nnd rcflecied rays? Whai arc the angle* of inciilmor wd ^>^ 
tion? What is the Inw of tvAorlion ? What roniliiiona inHiicncc the qunnliljr andiawMRf 
of ihc rellccivil ray? Whni is tntnimisrion ? Whni U obwrpiinn? I» ilie •b«rW'»!f 
dosiriinHiT What it Intcrfsrent* ? Hour mBji ini^rfcrmre ho illuilrnl«d? Whut tlaaP 
is pru^ncxil in light i«0ectod bjr rated turfoce* f Huw does ilio interference ilifftr bt» "^ 
piinuatic ipeclnimT 



^1 THEOnY OF COLOEATIUN. 103 ■ 

spectrum it is in the lower part, the orange and red being com- 
pifssed, and the violet and blue dilated. 

The colore shown by thin transparent substances, as soap- 
bubbles, and the beaiitiiiil tints of certain sLells, and such fine- 
ly-ruled surfaces, are all j)heuomena of interference. 

Refraction. — If a ray talU j)er])endicularly on a transparent 
medium with pai-allet surfaces, it passes directly thmugh it, 
and continueH its coui'se in a straight line ; but if it falls on the 
first surface at any other angle than a nght angle, it is bent or 
refracted from its original track during its passage through the 
medium, and on emerging fi'om it into the air is again bent, m 
that the eom*se of the emei-gent i-ay is parallel to the track of 
tlic incident ray. 

If the surfaces of the medium are not parallel to each other, 
the emergent ray will not be parallel to the incident ray, even 
though it is perpendicular to the first surtace. Advantage is 
taken of this fact in the construction of piisms, the surfaces of 
AvJiich are aiTonged at an angle to each other, so as to produce 
the greatest amount of refi-action in a ray. 

When a beam of light falls on the fir.st sxu'face of a pri?n) at 
the iji'oper angle, it is decomposed during its passage through 
the mstrumeut; and if the emergent beam is caused to fall on 
a sci-een placed in the propei' position, a sjiectrum is produced. 
If we examine the colors m the prismatic spectnmi as regards 
tlie amount of i-efraction, mc find that the red has been bent 
fi-oui its original course less than the others; it is therefore 
called the least i-efivmgible ray. The next in order of refrnnL'i- 
bility is the orange ; then tbe yellow, green, blue, indit,'0, \ iolft. 

Coloration. — -Reflection and transmission may both jjrotluce 
colui-s by the decomposition of white light; absorjjtion, also, 
may dec<tinpose light. When the absorption is perfect the sur- 
face seems to he black ; but ^vhen certain coloin only are ab- 
sorbed, and the remainder reflected, the surtace has the color of 
the i-eflec-ted rays. A red sui'fiice, therefore, owes its tint to the 
foct that it has ai)sorbed all the other colors of which light is 
composed, except the ivd, which is reflected; the same is the 
case with the yellow, violet, and other colors. When two or 
more colors are reflected, the suiface possesses the compound 
tint foiTOed by their union. 

Whnt is refraction, nnil how ie it produced? Whnl condition in necessary in order thni 
ihi: emergent my bIidiiIiI be |inrHllcl lu ttic ii]ciilcDt ray ? Wlint i« ihc order uf rcfraclion of 
■lie diflcronl colors orihc n|ipcinini, commencing wiili ihc Icbsl rcrmngiblc ? Does nbsorp- 
tion produce dccom pox i lion of liglii? Whni is i lie colnr ufu aiiiface tbnl alworbs liglit com- 
pletely ? Wliot in [he theory of colurntion of sarfnccs ? 



104 COMPOUND CMAJiACTEB OF THE SPECTRUM. 



LECTUKE XSXV. 



SPECTRUM AND LENSES. 



Tilt three Forcfg in the /^pectrvm. — Presence of Heat and iU i^inl of 
Maximum httensity <lennw»lrated. — Heffton of Maximum JnteMily of 
Li'jht. — AcfifiH of Yellow Hay on Compounds of Carbon, — JWmct 
of Vheinkal Itftyg demangtrated. — Pogitive and ne;/atioe ChemkalRayt, 
their Poirita of Maximum Jntenaity. — Lentea daasifitd, — Action ofew- 
vex Lenses. — Of concave Lenses. — Causes of Variation in focal Diilatf* 
tfconcex Lenses. — S/iherkfd Aberration described. — Correction ofSJier- 
teal Aberration. — Chromatic Aberration described, and the MetliXMof 
Correction. — Achromatic Lenses. — Penetratinff Pbieer of a Letia.—Jith- 
tion of penetratinff Power to the Diameter of a Lens. 

We have ilemonstrated that white light is composed nf sev- 
en (iistiuct colors; we are now to find that it also contains /i«rf, 
and citemiral or electrical rays, in addition to the illuminatiiig 
<>r liijht nti/H. 

If i\\f spectnira in caused to full on a Maekened suriiH* 
\\-IiiLii luL-j been nioi>itened with alcohol, or some other raporij:- 
ulile Uuid, it is found that the fluid evaporates with the great 
est rapidity in the i-ed ray, less in the orang;e, and least in the 
violet; we theretbi-e eonelude that in the sjiectnmi there are 
rays nf lieat sls Mell as ot" light, and the point of masimum in- 
tensity i.f tile heat rays is in the red. 

It' the lijiLCtruiii is caused to fall on paper covered with veiy 
fine print, we find that the finest print can "be read «-ith the 
LTveatcst facility and at the greatest distance in the yelUnv ray. 
The ptiint of maximum intensity of light, therefore, doci* not 
eorrespniid to that of heat, Iiut is found in tlie yellow ray.fro'H 
which it steadily diminishes to the upper and lower jiart of 
thi- spectrum. 

When a spectrum is caused to tall on a n>w of tubes whicK 
have been tilled willi water, and a jiortion of grass or some 
other vegetable substance jiliued in each of them, it is fowA 
that oxytreil is evolveii with tlie greatest rapidity in the tube 
in the yellow ray. The oxygen, under these circumstwicea, '" 
produced by the decomposition of the carbonic acid diasolTrf' 

Whnt are tlic iIiiec ri.rrcs foiitiJ in the fjjcclmiiiP IIciw mny Ihc iirrtcnoo rf bottt* 
It imrt of liio fpciiriim do i^e find ihc mnximum inicnuiy of boUT "'' 
m inlcnsiiy of light be iiboiiDF Whcro u it fuuiidf < 



TirE CHEMICAL RATS. 



1 the water, the vegetable material appropriating the carbon, 
sad setting the oxygen free. Since the action goes on with 

3 gi-eatest rapidity in the yellow ray, it fallows that, since the 

How is the region of maximum inteii.-ity of light, it is the 
ight, and not the other constituents of the suiilieuui, that is en- 

ged in the decomposition of the compounds of carbon ; and 
; that element is the chief constituent of the sensitive coat 
Eof the eye, the yellow ray is the most unendurable, and affects 
that organ with the greatest power. 

The presence of chemical rays in the sunbeam may be illus- 
trated by causing tlie spectnini to tial] on a sensitive suiface of 
iodide or bromide of silver, such as is employed in nialiing pho- 
togiaphic pictures. When the image is developtd in the jmtp- 
er manner, it is found that the deepest stain is produced in the 
portion whicli con-esjionds to the violet ray. The region of 
maximum intensity of the chemical ravs, therefore, diflere from 
those of heat and light, being in the violet. 

Not only are chemical rays contained in the spectrum, but, 
as Professor DrajK'r lias shown, there are two classes of chemi- 
cal rays, the positive and the negative. This fact may be ilhis- 
trated by causing the spectrum to fall en a ^■e^f■itive i)late 
which has been previously exposed to a light of moderate in- 
tensity. On developing the image, we find that it is longer 
than when the plate has been carefully protected from the 
light. The portion of the stain that con'esponds to the colors 
from the yellow to the violet of the spectiiim, and beyond, is 
deeply staine<l, while that which corresponds to the yeUow, or- 
ange, red, and the region beyond, is stained to a lets degree 
than the remainder of the i)late. 

The foregoing experiment duiinnstrates that in the region 
of the orange and yellow the iictiou lias been the opposite of 
that in the violet and blue, the fir^t undoing the work of the 
feeble light to which the sensitive plate was exposed, while the 
second increases it. In the first tlie action is negative, in the 
second it is positive. 

In the experiuients detailed above it is understood that the 
sensitive suiface is a bromide or an iodide of silvei'. With other 
surfaces sensitive to light the results differ, some allowing the 



tn uliich colnr nf iliir FrertrxiTa i* cnrbonlc nciil tiecomposed by vcii^tiililci wiili tlic cnst- 
CM njiiilii; ? Wliich (imv \» engafied in <bu dceciinpmiiion gf carbon cuni|«iindH ? Which 
mj hai ihe gramcBt intcnriiy of nciioii oii the wnwiive coat of ihc eye ? Ilow mny llie jupb- 
«nco of chemienl ray» in ihe ^[wciriim be dpni^iiiuiiicd? Ia whirb color of rlic ticrtrnni U 
Ibccliemiol force most inicnse? Hoivmny ilicexislcnce orpofiiivc nndnremiic iliuniicnl 
n be dcmonstralcd F 



IGti CHARACTERS AND PROPEliTIES OF LENStS, 

maxi'rauni effect in one color, and otliei-s in another. Any s_ 
trura ray raay show maximum according to the surface usea 

LENSES. 

There is a great variety in the forms of lenses, but w« 
rciliifi' them to two clasnes : Ist. Those which ai-e tbicke«.t 
the i.(iitie; 2ti. Thorpe whieh are tbickeRt at the circumfert 
The lirst \ve shall speak of as convex lenses, the second as o 
cave. 

When parallel rays of light fall on a convex lens, the)' I 
converged, ami, parsing fmiii the ojiposite surface, meet i 
i-nM«a each other at a certain distance from it, foniiingthe fue 
fivm which point they pass on, unless they are iutercepted,! 
Invome di\ergent. \Vheii parallel rajs tall on it concave 1< 
they diverge on leaving the opposite Kurface; they never me 
ami consequently the lens has no true focti«. 

The action of a lena may be readily understood V»y t 
ing the action of prisms on pai'allel mys. When the luv lil 
on the fii-st surface at a suitable angle, it is retracted toMi 
the base of the prism with but slight decomposition ; but I 
angle which the ray forms with the first surface may be 
rei;ul:itcd that the ray is Iwth refracted and entirely d« 
pMSi(i,jind a spectrum formed. 

The tiiNt ctmdition is that which exists in a lens, for we t 
■ i-eganl a cou\'ex lens as Wing comjwsed of a gi-eat nunilitf 
sections uf jirisms. st> arranged that their liases all meet at 
tvntn- of (he lenf. The action of a prism is to i-efi-act the I 
towai\l its Iwise; all the prisms of which the lens is ct>nipo 
then-fore ivfraet the rays towanl the line passing thn)tigb 
centre of the lens, and, trausing them to cross each oCber t 
short distaoi-e from it.pri>iluce the ttH-us. 

In the i-oucave lens ou the coutran,-, the sections of j 
are arranged so that the l>ases aiv at the ciirumfereoce of 
lens, consequently the ravs are refracted, so that they i 
fixuu its axis and ixH^-ome divergent. 

The focus, or ix>int of enwsing of the refracted ravs that li 
jvi-isetl through a eiuivex lens, varies in its distance from t 
surface. The conditions which govern the distauci- of the fo 



What b the tonililtna «f th« cbrminl 
knwi be rcdiiml i WhM 
tkr ftwu oTa k«u> Vi'hM b ihc Httim t€ 




r 



SPnERIOAL AND CHROMATIC ABERRATION, 107 

are, first, tlie curvatures ofits surfixces, and, second, tLe distance 
of the olijeet. 

In lenses of tlie eanie diameter, tliat ■\vliicli lias its sulfates 
desoiihed by the shortest radius, or,iu other words, that which 
is thickest in the centre (providing the circumference in all is 
equal In thickness), will have the shortest focus; and the less 
the couvesity.the greater is the focal distance of the lens. 

The variation of focal distance, caused by variation in the 
distance of the object, is due to the fact that when the object is 
close to the lens, the rays emitted from its surface are diverg- 
ent, while as it recedes from the lens the divergence is less, un- 
til tinally, at gi-eat distances, they viitually become parallel. 
When the suns lays are employed to detemiine the local dis- 
tance of a lens, we are dealing with jiarallel rays ; but when an 
artiticiid light is used, unless the distance is very great, we em- 
jiloy divergent rays, and the lens has inci-eased work to accom- 
phsh in onier to bnng the rays to a focus; it consefjuently re- 
(juirex increased focal distance. 

In lenses of the same focal distance, those Mith the gieatest 
diameter give an image which is very indistinct when com- 
piired with those of small diameter. This is due to the fact 
that the different pails of the lens do not Ijriug the rays fall- 
ing on them to the same focus. It is called fpJtei-ical aha-ra- 
titm. and may be relieved by reducing the d!;:nieter of the lens 
by the use of a stop. It may be greatly reduced by giving the 
two surfaces of the lens different curvatures. liadii of cinva- 
ture in the ratio of one to four, or six, are commonly used, 
Such are called crossed lenaes. 

The image produced by an ordinary lens is not only indis- 
tinct, but also colored nti its edges. This is called c/ironuitic 
nberridloii ; it is coriected by the use of compound lenses, 
formed of crown and flint glass, ground to fit each other accu- 
rately. Though each of these glasses give a chromatic image 
wlien used alone, that formed by the compound ni nmgement is 
entirely free tVom C(dor, the eiTor of one lens completely neu- 
tralizing that of tlu; other. It is called an acliromatic leU'*. 

In lenses of the same focal lengtli, that of tlie greatest aper- 
ture has the greatest remh"iii(/ /loirpr, liy wliieli is meant the 



■^<^-' Whnl U >i.liorinil 
:<: reliei-ed ? H.»v mihv 
<ikJ ? Iluw is tplicrk-ul 
It nieiint by iIib penetrnting 



IJoei lliB Ibih of llie 


lintioii in tlie di-lnin' 


1901 of the mma TrM.-. 


»rmtiur>? >lo» ix 1' 


1w ci,rrect«l ? Whii 



poirer of a leni? Wlini deienuiiiai tlioi-eiiolringpoiveTOf aieiw? 



THE STItUCTUnB OF THE EYE. 

power to define fine lines and discover mitinte markings 
Tlie term penetrating power is now used in the same seiisM 
as focal depth. It is a property to be especially desired in 
biological reseftrcbes. It is best sliown by lenses &■. low angil- 
liii' aperture. Resolving power and penetrating power are of 
especial significance in connection with microscope objective*. 
Different opinions ai-e held regarding their relative value under 
different circumstances. 



LECTURE XXXVI. 

AKATOIIY OF THE EYE. 

77ifi Orbits. — S/iape and Diameter of the Eytball. — Its Tnnica or Coatt ^ 
— TAe Sckrolic.— The Cluirokl—The Black Pigment and t/it Itttii'im.-^ 
deicfibed, — The Cornea iiml the three I/iiinors. — Tlieir niathe liiM'ti/ -^^ 
— JTieLens describeil.—Thf, Jlyaluiil Membrane ami ila Kaiictioit.— Pi^ .»^ 

Jria, its Comjjo/iitiait and I''it»ction, — T/ie Jietiim and Optic Chhtm. 

The Appendauea. — Position of the Musclen. — The Cottjunctivu—Th-^^^ 
Lachrymal Olaml and A'asal Dvct. — The EijeVuh^ Glands, and lAt'lii*.^^^, 

TiiK eyeball is jilaced in the orbital cavity, 9<j that it is pr^*. ^ 

tected from violence and injnry on all 

sides e-Kcept anteriorly, and even there 
I ia shielded as much as jiossilde by the 
roverhanging brow and hard nng of 

bone which surrounds the bases of 

these cavities. The axes of the orbits 

are in the lower animals very divei^- 

ent, so as to give them power of seeing 

laterally to a con.mlerable extent; but ro,tu«.rfF:T,b.nt.ortiw.*-- 

in man they are nearly parallel, and di- 

i-erted forward, lateral vision being obtained by the movem*^ 

of the head on the vertebral column. 

The globe of the Viall is over one inch in diameter, ami n^- 

ly spheroidal in fignro, the lateral diameter being the short*^^ 

It is conijHJsed of three eoata or tunics, the sclerotic, choro*^ 

and retina. The sclerotic is formed of dense white fibrous * *^ 

sue, and giva-? to the ball its figure and white color; to it t *-** 

muscles are attached. The choroid is the vascular coat, c*-*^' 

sisting of arteries and veius, and lined interiorly with blu^^' 




TTuw U iho pyclmll piinocw.1 ? WImi i- 
How ii intenil viaion obMiricd in niHii? 
iiinn? Kama the ihree liiDlca ofilie liiill. 



■lie rchilion of llie nx«i i>{ tlie ortiiw lo mcii '«'|^' 
hVliiii U ilie Bhn|ic nntl iliiiinetor cif ili« ctcbaH ■* 
Describe the H'leroiie. Dewribe Ilie chorai^ 




expansion of the optic m?iTe, 

Fig. 1 oO, a a, the coniea ; r, 
retina; ;', iris; f, lens; ?», ante- 
rior chamber of a^jueoufl hu- 
mor; w, posterior cbanilter; d 
?■' r, ciliary body ; c, vitreous 
btinior; o, optic nerve. 

Tlie organ of vision may 
with advantage be studied un- 
der three distinct divisions : 
1st. The optical mechanism; 
2d. The nervous mechanism ; 
"aud,3d.The appendage?. 

The optical meehauLsm consists of the cornea, three humors, 
the ins, and the screen, or black pigment. The cornea is shaped 
and fitted into the sclerotic like a watch-glass into its case. It 
19 composed of a transparent librous tissue, and sen'es to give 
a convex figure to the humor which lies behind it. 

The three Immors are the aqueous, ciystalline, and vitreous. 
The vitreous is largest in quantity, oceupyine; about four fiftlis 
of tho bulk of the eyeball ; the aqueous is the most ihnd, and 
lies immediately behind the cornea; while the crystalHne hu- 
mor is the densest, and is situated between the aqueous and 
viti-eons humors. 

The ajjiieoim humor is divided into two portions by the iris ; 
that which lies between the iris and cornea is called the ante- 
rior chamber, and that between the iris and crystalline lens is 
called the posterior chamber. 

Wliere j> ihe black iiicmeni ? Deecribe ihc minn, Unilcr whnt dlriaions a iltn e^c de- 
Kfibcd ? W>iat parls cninpoiie iIip opiicnl mechnnisin ? I>c3<'ril>« ihc cnriiFn. Whut U itb 
n? Kiinic ihc ilirco Immnrs. Which is gremrEi in bulk!' Wliiih is inn<[ lliiia? 
is mosl dense? Whnt ia the reUlivii position uf each linmor? Whal arc iho anw- 
d posterior chambers? 



170 



THE 1RI3, BLACK PIGMENT, AMD RETINA. 



The crystalline humor or lens is double convex in figure, the 

Eosterior eurface being the most convex ; it is held in position 
y the ciliary ligament and muscle. The lens is jierJ'ectiv trans- 




CTyetaUiiHi Ltfiu. 

parent, and composed of fibres, the edges of which are dentate 
nr sen'ated, like the toothed cd^e of a saw ; the teeth ot" udjoin- 
iiig fil ires, interlocking with each other, give givater firmness to 
the leiif. 

J'/ie vitreous humor has a density intermediate befrvveeu that 
of the anueous and crystalline j^_ ^^ 

humors; it is held in position, 
and the formation of cuireuts 
avoided, by the presence of a 
delicate membrane, which 
tra^"el■se3 it in every tlirectiou, 
called the hyaloid inembraue. 

Tlie iris is placed in the 
aqueous humor, separating it 
into the auteriorand postei'ior 
chambers. It is eouiposed of . 

muscular fibres, some of which ^■'"™* """""■ •'"""« '*" '""^ " 
pass circidarly aruun<l the central opening or pupil, while th 
others are arranged as radii, extending fi-ora the margin of th 
pupil to the insertion of the circumference of the iris into th 
sclcj'otic. Wlicn a strong light falls on the iris the circuit 
fibres contract, and diminish the opening of the pupil. 

The hlaeh 2>iO'^ient is the inner layer of the choi-oid or ntij 
die coat ; it is the screen of the eye, on which the humors liria 
the images of olijects to a focus. 

The retina is iormed l»y tlie expansion of the optic ner^-e, ti 
portion ue.\t the black pigment being the most sensitive. Tli 
optic nerves do not pass directly from each eye to the « 




riiofiliolenKF UnwU.. ..^ 
re drnaiti uflhc v 



1. iiiii IB iiiL- ii);un: iu iiju iL'iiK r i]in> u il iiviu hi jmsiiiun f .iiiiil i* iir< 
llic \<-nt1 Whni islhervlKlivedrnaitTorihc vitrcuus liiini<ii' ? Wlml U Chi 
brnnc? Wlinl u the tiosirlan if the iril? Ofivhrit lissiic^ » Jl romnosrit? 
rthrc« of ihe irii nrrnTtpcd? Wlinl i» iheliniiil? Where U the binefc |ii(;ni 

tha mlinn ? Whirh nnri in Efip mi^t wnnWtvt^ ? 



Wbich pnri ii ilie moct scDsil 




THE APPENDAGES OF TUE EYE. 171 

eiile of the brain, but tbey meet at a short distance behind the 
orljita to form the optic chiasm, in which there is a crossing and 
intercbaup;e of nerve fibres, so that a portion of those from the 
right eyt' pass to the same side of the brain, some to the left 
heiuisjiheif, and othei-s to the left eye. Those fiom the left eye 
pass to the left and right hemisphei-es, and to the right eye. 
There is, consetjuently, a peifect and free coninmnieation be- 
tween the eyes, and any cause which aft'ects one eye is almost 
certain to i)r<'iluce disturbance in the condition of the other. 
•i^'J7itf <tji/n it'htgm of the eyeball are muscles, an exteiior mu-. 
cous liieiiibraue, the lachrjmal apparatus, the lids, eyelashes, 
and eyebrows. 

The vniackH of the ball are six in number ; foni* pass from 
the apex of the orbital cavity to be inserted into the upper, 
lilower, inner, and outer parts of the ball : they are called the 
recti muscles, and are designated re- 
spectively as the internal,/, external, 
e, superior, h, and inferior, c, rectus. 
The other muscles pass obliquely from 
the fides of the omit, and are known 
as the oljHquus superior and iuferior, 
<j, while the nmscle which raises the 
ujiper eyelid is called the levator pal- 

^1 Ihe mucous membrane oi the eye is 

^Balled the conjunctiva. It covers the cornea, the anterior por- 
HBon of the sclerotic, the inner surface of the lids, and is contin- 
^nous with the mucous nieiubrane of the nasal eavitj'. The por- 
BKion of the coujunctiva that passes over the cornejv is perfectly 
transparent and invisible, except when the vessels ai-e injected 
by inflammation. 

Tii'^ htrhnjiiial apparatus consists of the laehi-yraal gland, its 
ducts, and the nasal duct. Tlie gland is placed in the upper 
aud outer part of the orbit, and funiislied with a nuniljcr of 
small duets, Ijy which the secretion is delivered on the cou- 
junctival membrane of the ball. The nasal duct commences at 
the inner angle of the eye, and terminates in the nasal cav- 
itv. 







delivoi'ei] on tlic rai^lunciiva 7 



iLTi-;; Abrus from tliu rotinn 
■ ..f ilio oyo? lIo\¥ itinn,v 
il tlicrorii mntclex. WhnI 
iilinino "f Ihe CTO? Whut 
iiniion on Ihe tniTupnrenry 
iii>? Where U the li><->>rv- 
Where is the niual daci ? 



[ 172 THE ACTION Of THE HrMOBS AND IRIS. 

The lids are composed of ekin externality, and mucou* niem- 

I lirane uitemally. The upper lid is pmvided witli a disc of 

I ca!tilai;e, Mhiob gives to the lid its figure. On the edge- tif 

both lids there is a row of glands, which are placed Iietween 

the hail's or lashes of the lidw ; inflammation of thesie glands is 

ver\' uoinmon, and is genej-ally known as sty. 

ulie etjtihrovs are forrtied of fhort hairs, which are arranged 
in such a manner as to direct the pei-spiration as it flows do\»-n 
the forehead on each side, and prevent its j)assing into the eves 
and interfering with vision. 



LECTURE XXXVII. 

TIIE ACTION OF THE EYE. 



I 



TTte Junction of the t/ure Humors. — T/ie Action o/t/ic Irtg. — Ailjiigtnteiti 
/or D^ff'ermce of DUtauce ofdrff'trent OhJfPts. — Jlft/iod i>f t'orreetton 
of t^lifrical Aberraliwi. — (.^omcfioti of Chromatic Aberration. — Ac- 
tioti of black Surfacea on Lig/U. — Action of the Ocellus. — Action of the 
Compoutui Eye ^fa Fly. — Action of the ilye in the Hiyker Animale. — 
Action of the JUuecke of t/ie £yc. — Of the lAxckrymal Apparatu*. — Of 
the Lids. Lathes, and Ey^otes. — Zomjaiffhtedness and l>iiort«iyhte<inf»» 
described. — Method for relieving them. — Cataract described. — Ojiera- 
tiousfor its Itelief. — StrahiMnus. — Petndiaritie* of the Optical Ajifxintttit 
in the Louder Animals. — C<m»litiition of Areolar Tissue. — Adipofe Tis- 
awe, its Fonnation, and Tenacity of certain Positions. — Detcriplion tf 
the Skin. 

The action of the eye may lie studied under three di\-i.s!on9: 
1st. That of the optical portion; 2d. Of the nervous portion; 
and, 3d. Of the appendages. 

The humoi-s of the eye, taken together, form a lenticular 
combination, which brings the rays falling on the cornea to a 
shai-p focu9 on the black pigment. 

The iris regulates the quantity of light passing into the in- 
terior of the^jall. When the light is intense ttie pupil con- 
tract!*, and when it is feeble it exjjands, so allowing a greater 
or less number of rays to enter the oi^an. 

Tlie adjustment for variation in the distance -of various o)>- 
jects is accomplished t>y the ciliary muscle and ligament, which 
alter the distance of the lens from the black pi":ment^ and also 
change its curvature by compressing it at the circumference. 

Wltnliilliepomposiiionofiliccvdiil*? Where smile elnnJ* of (lie lids? Whubnivr 
WliBl is ilip funciton of iho liomnrs of ilio cvt ? Wh«[ i» rhc sciiun of ibo iri»* Iloir )■ 
cbe ■4jaitmeiil (or variation in ibo<liU>iK« orobjocuobuiM)!? 



^^^^V ACTION OF DARK SURFACES. 17» 

The correction for spherical aberration ia accomplished byB 
the vaiyiiig ilenHity of the difterent parts of the lens, ami then 
contraction of tlie iris, which reduces the diamet*tr of the beamj 
of light eiiterinj^ the eye, M 

In order to understand the ftinction of the nervous mechaD-l 
ism, we must fii'st examine the action of black suifaces on light,fl 
Franklin found that if small pieocH of cloth, of various shades^ 
of color from white to black, were placed on snow on a elearj 
winter's day, tliey absorbed the sunlight, and melted their wayfl 
to diliereiit depths in the suow. The colors he used wemw 
black, dark blue, pule blue, greeu, purple, red, yellow, and other i 
shades, up to a pure white. In a short time the black had 
passed out of reach of the sunlight ; the dark blue was almost 
as deej) in the snow, and the otliers had sunk to a less extent 
as their color was lighter, the white cloth remainmg on the sur- 
face. Sir Humphrey Davy made a similai- series of experi- 
ments with pieces of colored copper, each one inch square, and 
of the same weight and density ; one was black, one blue, one J 
green, one red, one yellow, and one white. On the middle of I 
the under surface a small portion of a wax cement, that meltedj 
at 7('', was placed. The strips were then placed on a piece of a 
board painted white, and exposed equally to the direct rays oPj 
the sun. After a short time the wax on the black plate com-l 
inenced to melt, and the others followed in the onler in whidJ 
they have been mentioned; but the white strip showed noM 
tendency to uielt its wax until that ou the black one was enij 
tirely fluid. I 

In the lowest grades of animal life, we find that the ocelluS),V 
or minute eyes of animalcules, consist of a nerve which tentt«B 
iniites in a hwip covered with black pigment. In such crea-f 
tures,the light,fallingon the ocellus, is converted into heat, and I 
the animal feels its way to the side of the vessel which is most 1 
perfectly illuminated, or hides in some dark rece^ to rest, it8-^ 
njovements Iteing guided by the variation in the tenijierature I 
of the ocellus. ^ 

Passing a little higher in the scale, we reach the comiwund 
eyes of insects, such as the fly, in which the coniea is composed 
of a vast number of small liexagonal comes, which are the 
bases of an equal number of pyramids, the apices of which J 
meet at the optic nerve. A filament of the nerve passes intoB 

How U tphnTKn] nberratiun corrected'^ Dcscrihu Fmnklin'!! experitncni. Wliy dlil tha ■ 
Uni'k nieces of cliilh aink lo iha KreateBt depth? What is llie fimplesl form of ejc? Jlow M 
<lue> ilie ucelliu nci ? Describe Uie comjiound eye uf Llie li}~. Uow does it nel ? ■ 



I 174 ACTION OF THE APPENDAGES. 

the apex of each pyramiJ, aod is covered with black pigmeii 
8o that the creature can not only feel the presence of tue ligli 
but can also determine its direction, and the outline of the h 
minoua object. 

In the perfect eye of the highest grades of animals the priiicE: -= 
pie of action is the same, liie optical mechanism brings ihw ^ 
rays to a focns on the black pigment, wheie the image of Hglr :^ 
is pei'ceived by the terminal tnbes of the optic nerve, wlncK ^ 
nbnt in iiitiiiite nnmbers against the Vilack pigrntttit. Thence 
pftssiug along the optic nerve, the impressions received bv lh»- 
tubes of the retina are conveyed to the brain. 

The appendages may be divided into the motive and iiroc: 
teetive. The fii-st give to the ball its movements, the retti Amr 
reeling it respectively npward, downward, to tJie light, and li^ • 
the left. The oblique muscles ratate it on its axis, and aid ica 
giving to the eye the variable expression of which it is capable 

The laclii-j"mal gland furnishes the moisture Avliicli ])re^erYegt 
the conjunctiva in a transparent jstate. The pecrefion is etjualS^ 
ly dift'used over the anterior surface of the eye by the lidt* tirsr 
touching at the outer angle, so as to sweep the fluid fumishe<E 
by the glaud over the surface of the ball, and wash all dust o* 
wther foreign substances to the inner ar.glc, wliei'e they are con- 
veyed by tlie nasal duct to the nasal cavity. " 

The eyelashes aid in protecting the eye by causing the sud--^^' 
den closure of the lids when any object touches them; th*^;;^ *' 
eyebrows, as AVe have prevjouisly stated, direct the persijiiation^r*!' 
as it flows down the foiehead, and prevent its passing into th(S=^ * 



^ Of the diseases which affect the eye, none are of greater in — 
terest than long and short sightediiess. Tlie first exists in ohl,^ 
and the second in young people. The causes of shortsighted — 
ness are, too great a length of tlie glolie, too gi-eat a cnrvatHiti* 
of the cornea, too liigh a refractive i)o«'er in the humors, roti- - 
stant use of the eyes in looking at minute olijeets at a short ^ 
distance, and Iiereditaiy tendency. In this condition the funia* 
ot'the eye is shortened, so that the iuinge falls in front of the * 
Slack pigment; the object must therefore be approaclted close* 
to the organ in oi'der to throw the focus backward, anvl pro- — 
duce a sharply-defined image on the pigment The longsight- 

Wlint in ihe metliuJ af nclion of tlio eve in mnn nnd tlie tiighest f;rRcl«« tif nnimalH t Wliit 
is (he fuiiciion of [lie rerii muwles? How ilo tlie ohliqiie dpi? Wlmi is tlic uh i.f the luHi— 
rvmnl "ocreiion? Where do iIib evpliiU loucli first f How i« ihe laflinmnl rwniinn lln^Ht* 
(l*li>I>OB0<l of? Wlinl is tlieruncliuii of tlie eyelaslini! Wlint is llie nljjecl i/ilie e.iclin.nl 
Ai nlint period d( life <loe» iongsigliledneui apjicnr? Wlieii inut i-liuitui{liiediiBu omir' 
Wlint niv rlie cnuie* of KborttiiKiitetlneBs ? of lunBniBhteUnuiui 7 Where docs the (ueiu (kll i> 
■lioruiglitediieMf 



r LONQSrOHTEDNESS AND SIIOUTSIOHTEDNKSS. 175 1 

E(3ne9s of old age in owing to the loss of contractile power iu I 
the ciliary rausule, antl diminished elasticity in the crystalline I 
lens; the focus t'tills behind the black pigment; the objecfcl 
must consequently be placed at a greater distance from thea 
eye, to bring it to a sharp focus on tlie pigment. I 

! Shortsightedness may be i-elieved liy the use of concave 1 
enses, which cause the rays to diverge as they enter the or- I 
gan, and so tlimw the focua farther >)ack ; longsightedness, on J 
the contrary', requii'es the use of c(m vex lenses, which convei^ j 
the rays, and, bringing the focus fonvard. cause it to fall on I 
the pigment. Iu the selection of glasses*, the lena tor eacheye J 
shoula be chosen sejnmitely, ttiv there is usuall j' a diffei-euce in I 
the foci of the eyes; and if lenses of the s:ime focus are used I 
under such conditions, one eye is apt to be strained, and more J 
Bless injury of the organ i)rodueeii. J 

■The various tissues of the eye ai'e, liable to rheumatic, oi'dUl 
Hty. and specific inflammations, which shoidd be immediatelvl 
placed in the care of an experienced jihysician ; for it is to nol 
reraemV)ei-ed that the eye is very delicate, and inflammation, ea*! 
pecially \\'hen produced by some specific cause, is apt to I'esult.a 
111 its suddeu destruction. I 

In certain families there is a predi9p<}9ition to the formationS 
of an opacity uf the lens, called cataract, iu M-hich it becomesB 
perfectly opa(|ue, and the passage of light to the interior of the 3 
eve Ijeiiig cut off. As long as the disease exists in one eye I 
only, it is best to let it alone ; but when it exists iu both lenses, I 
ami useful vision is lost, an operation may be peiibrmed, which, I 
in the majority of eases, results in affording the patient a veiyl 
fair degree of vision. I 

The operations for cataract consist in either passing a suita- j 
ble inatniment through the cornea, and dejiressing the opacpie 1 
lens out of the axis of vision, or in making an incision in the I 
coniea, through which the lens is extracted. Inflammation is, j 
of course, pi-odnced, and loss of both eyes may follow an ojieva- I 
tioii on one. Such treatment ought, theretbre, never to be I 
tpted until all useful vision is lost. | 

'iquinting, or strabismus, is caused by an undue contraction I 

the extenial or iotenial rectus muscle; it may be relieved J 
^ catching the muscle on a suitable hook, drawing it fonvard, ] 

Wliprc lines llie fouuafnllin lonBuiEhloclncM? 
llchredncu ? Univ ilc> ihcr nc! ? Whnt Jen»e» i 

tihoalil ihe letiiM bo clioscn sppiiriilely fur 
ddoeblindiieu? Under nhalci 
Ibo Qjicmlioiis fur caturni 



lU dam i.f |ciisp» 111 
i-l.>n4i'l.tc.{i<t'.;3? 



r 



I 

I 
I 



.176 coMPosmoN- Of abeoijUb lasBvaL 

antl severing it mtli a pair of scissors, TLe operation is not 
always suoeesftul, tur the eye is sometimes turned in tliu ii|)pi> 
eite direction. 

The lower iininiak present various jiecuharitiea as regards 
the eyes, among whit-li we may mention thi; chameleon, in 
whieli the eyes are placed on sterna or stalks, and ai-e capalil"- 
of iiiilependent motion. In the caruivura the eyes ait*, verj' 
lai^e compared «-ith the size of the animal, ami the exterior 
wall of the orbit is composed of ligament, which allows tie 
eyeballs to be pressed outwai-d, giving to the civature n pecu^" 
iarly ferocious look. In the herbivora, uu the coiitrar;-, thej 
are small, as in the elephant. In the burrowing animals, ^ 
the mole, they are very minute, and in fishes which inhabit tJ*" 
waters of caves they are reduced to a nidimentary c(inditir>**" 
In hinh there is a third eyelid, which passes trausverselv nu>^^ 
the eye, to which the name of membraua uictitans is givtn. 

In emmierating the organs of 
the liody, the areolar or connective 
tissue, and the skin, were mention- 
ed. The areolar tissue is comjiosed 
of yellow elastic and white inelas- 
tic tibres, which interlace with each 
other in every direction, to form a , 
tissue filled Avith aivohe or spaces. ; 

When the ai'eolar tissue is em- 
ployed for the purpose of connect- 
ing muscles or retaining organs in 
their pi-oper position, it is loosely 
woven, so that the ai^eolaa, or cells 
formed by the fibres, are of consid- 
erable size; but when it is employed to form membranes, it is ' 
then closely woven, and the cells or spaces disappear. 

TTie connective, or, as it is oflen called, x.'ellular tissue, lies be- 
tween all the muscles and organs of the body, and there is a 
perftH.'t communication among the spaces or cells, as is demon- 
strated by the fact that when the ribs are fractured, and the 
lung wouudeil so that the air passes into the cellular tissue, it 
quickly finds ita way between all the oi^ans of the body, and 

Wlinl h tlio pcculiurilv in llic cjcs of iho cbBinrlcoii ? How Jo llic fyn of tlie comirnrii 
n)lii|uirc in tixc wiili llic livrbivorn ? WliBl givi-H lo lli<> cnrnivoni ihcir rcrncinni appiPiP- 
■iico? What il llie popiilinritjtin ihe pyc» of biirroning niiiiniil« like ihe mole F wIiai » 
tlie membmnn niciitniuT Whni it ilio niin|>aBitii>norntTolnriiuiiD? Under »lml ciirnm- 
finncnilnn the icxiuro of connective tiHuo vorj'T Uow it Uic communKaiion of the rclb 
vt urcolBt tiasue dcmunxrued t 



Cell ulu Time. 




THE AREOLA!: TISSUE AND SKIS. 177 I 

the areola or spaces become filled with the gas, and the body | 
disteniied to an unnatural and dangerous degree, so that incis- 
ions in the skin have to be made in order to I'elieve the sufi'erer. 
In the cells of the areolar tissue fat globules 
are deposited, forming the fatty or adipose tis- 
sue. By this device provision is raade for a 
very considerable deposit of fatjAvithout inter- 
fering with the action of any organ. There I 
are, however, certain localities in ivbich fat i"* I 
mains In considerable quantity, even to the I 
last point of starvation ; among these ^\'e may I 
mention the orbits as most prominent, a cer- ] 
tain proportion being required to form a cush- 
ion for the eyeball, in order to give it proper J 
siipixirt. 

Ihe skin we have already described in part J 
when speaking of the organ of touch. It consists of two lay-- 1 
ers, the external epidermis or cuticle, formed of epithelial cells, J 
which are worn a^vay by contact "dth hard external sul)- ] 
stinces: it is reproduced from the inner layer, called the cutia j 
vei-a ( tnie skin), or derma. 

The derma is composed of areolar tissue, blood-vessels,] 
nerves, glands, and hair follicles, all of which have been de- 1 
scribed in pitn'ious lectures. The function of the skin is to I 
fonn an external covering to the tissues of the body, and pro- [ 
tect them from the action of air, water, and external violence, j 
while the areolar or connective tissue holds each organ in its | 
I)ro|}er place, and retains the skin in contact with the tissues it ] 
protects. 

How is fatr; or adipose tisKUO formed ? Or what pan a( the IhhI; ia the rnttv dpposit m 

lenadimit ? Ofivliat )isrM is thuikm composed f Dracribc tlie denns. What U the fuse- I 

■' oofilieskin? ]yi ' 




HUMAN LIFE, 



LECTURE XXXVIII. 

THE COURSK OF HUMAN LIFE. 



T/ie Periods in the Life of an Indtmdwd. — Size of thr, new-bom Jnf^ 

— RiUe o^ Groxetk. — Aceraffe HeifffU ofAdulCa. — Maj-ima and Mint 

of Height. — Wtight at Sirtk. — Average Welffht of AduUs. — ftWoi^s^'/ 
mammum Weight. — First AUernpta ai Articulate tf/iccch. — Relation^ — — '" 
tlus Vegetative and Intellectnui Rowers to each other, — £videnves of li ' 
Influence on each other. — Decline of Inldlei-tuaUty. — Average Jhin ' 

of Life.— Mortality <U different PeriodH.—Inftumce of Hex and Si' 

on Mortality. — Inetancei of great LongrAnlg. — Approach of Dtull^^^' 
Tfie J-hdea Hij^iocratica. — Intemtitinl Deuth. — Period of Rgmii ■ ^ 
Slrcji. — A mount of Stee/i regitired at different Periods of iife, — Oi ^^ 
in tehiefi Sleep subverts t/ie Senses, 

CosiMESciNO with bis biitli, the life of man may be diviiS^' 
into the four following periods : 1st, the infantile ; 2cl, the a*^_^ 
lescent; 3tl, the adult; 4th, that of old age. We tlieiefi.^^ 
pass next in oidei* to the detailed consideration of each of th^ * 
periods, in the sequence in whicli they have been mentione(^t-i 

The average length of the newly-born male infant is 1 * 
inches, while that of the female is 18^- During the fiivt fi^""J 
yeai'9 the annual rate of gi-owth is I'apid ; Imt it gradually ^" 
conies less and less, until a uniform annual rate is estaltlish * 
of about '2\ inches, which continues from the fifth to the s: -^ 
teeuth year; in the seventeenth year it is al:out li inehee, aK^ 
during the eighteenth and niueteentb about one inch. 

The full growth is usually attained at about the age •■ 
twenty-one, but many persons continue to gi-ow to the t\\'eii*" *^ 
fifth year. The average height of an adult, according to Qi-*" -'T 
telet, is 5 feet 8 inches. He also states that the niaxiuiimi -* '* 
8 feet 3 inches, and the minimum 1 foot 5 inches. 

At birth boys are heavier tlian girls; the average weight 1.^^^ " 
ing 6^ lbs., the maximum 12i, and the minimum 2^ lbs. Di-*' ^""^ 
ing the fii"st week of infantile life the weight diminishes slrgl^ '^^}' 
ly, owing to the action of the aerial form of resjuration; ^ 
then increases rapidly, tri])Iing in the first year, doubling t]]»-~*£' 

Wlintaruihefourperiadiinilicliri^ofan indiridusl? Wlmi in the length of n ncwl 
inr.int ? At whttipcrioj is the nttc of growth moni mpidF Wliitt imht! raw froolthi' 
to tlie sixteenth jenr? At nhat n(:c U the fnll eronlh attniticil ? What U this arrl 
ItciKhl? WlinC nrc the mAximn unci minimn of lieighlf Wlint i< the averagr *" 
birth f Whnt arc tho mnxitnn nnj minimn uf wdght nl birlli? What cLt 
ing ilie fint week of InfanTilo life ? 




THE VEGETATIVE AND INTELLECTUAL LIFE. 



in the following six years, after which the rate liecoraes less 
and less, the maximum lieing reached at the fortieth year; it 
then i-emains nearly stationaiy until the sixtieth year, when it 
commences to diminish until <leath. 

The average weight of men between 25 and 40 is about 140 
lbs., and of women 120 lbs.: the healthy maxima and minima J 
iu men are 216 lbs. and lOS lbs. ; in women, 20G lbs, and 87 f 
lbs. 

As the human being develops in stature and weight, the iu- 1 
teilectual powers als(> increase in perfection. At its entrance | 
into the world, there ts no other mammal so utterly dei>eiideut, 
BO weak, and void of intellectual power as an infant. The or- 
gans of special sense seem to l>e perfectly developed, but they 
are not employed, and the future hero lies in his cradle a help- 
less mass of imbecility, scarcely showing his existence save by J 
cries of pain, and spending his days in eating and sleeping. 

Gradually, as it increases in size and ^veight, the infant be- 1 
gins to obtain the use of its special senses, and, ovei-coming thel 
state of stupefaction produced by the numberless objects it raetT 
on its entrance into the world, it commences to recognize thoseJ 
by whom it is surrounded, and i-ewaixls the anxious care of its-J 
mother with sunny smiles. I 

During tins early period life is absolutely v^^tative, but at I 
about the twelfth or eighteenth month the infant commenceal 
to gain the power of nrticuhitf speech, which se^ms to mai'k the I 
ejjoch at which the mind obtains the ability to concentrate it- f 
self on one object or sensation. As the age advances the in- 1 
teilectual ])ower rapidly increases, until at t^ie period of puber- J 
ty it predominates over the vegetative life, which up to that! 
time is in the ascendant. 1 

The mental and intellectual jOTwei-s l-each their zenith at j 
about the fiftieth year. They are most intimately connected 1 
with the jthysical cunditinn nf the body, and the reaction of ( 
the mental and aniimil indiviilualities on each other are de- J 
monstratt'd by the facility with which we select the intelligent! 
from the liabeclle by the expresision of their faces, or read the! 
tlioughts and ideas which illuminate the countenance before! 
they assume the form of speech. 

When ia iLe niaxiniiiin ofnciglil nimincr] ? When docii llic period nfileclini 
'WhntUtlio sTcroBC weight of aJuUs? What ore iho maximn Qnd miminia? Whal in 
vondiiton of the new-lmm inrnnt? At whnt period Uthb power of sriicn late Kpeecli gninnlf I 
'^Vhat rhitiica i" >i>e mind occurs at Ihe aaino tima ? What is the relation of llie TcgPlniira I 
10 iho intetlccinal powcn nt the dilTercnt petiodi uf life ? At whst age docs iIiq intrUivt I 
narh its mnximum ? WhnI are ihe cvidances (if the Influences uf Ihb vh;iical and in'el' ] 
Iccinal poffcn □□ each other ? 



DITRAT30H' OF HOMAIT JJFK. 



Soon ."ifter the intellect lias reached its iiin.ximnm tlie peri*^ 
[ of decline enniiuences, and not onlv the special senses, but als* 
[ ideality and reason, begin to fail, the passions \obc their iute***^ 
ity, ambition its sway, and as old age gradually steals upon i:!*^ 
, great statesman or humble laborei-, they fall alike iuto t:l»*' 
same condition of mental imbecility which they presented o'' 
theii' entrance iuto the woild, eveiy species of exertion becoy^' 
ing irksome, menioiy more and more obtuse, the last acts of *»" 
feventftil life being the first to fade away, until at last only t J**' 
recollections of the associates and joys of childhood are retai*^ 
fd, and the child of a hundred years dozes quietly and dreax'*-' 
away his life, ^raitiiig for the death-deep to close his ej'es i*:>*^ 
ever. 

The average duration of life is about 33 years, the morlali*^ 
being gi-eateat in its earlier peiiod. About 22 jjer cent, of 1 1* " 
births are lost before they reach the close of the first yeai-, nW^* 
H7 per cent, before they reach the sixth, and at twenty-fi "*^ 
half the births are lost. 

'riie I'atio of mortality is gi'eater in cities than in the cot» * 
try; it also increases among females between 14 and 18, at^*- 
during tlie peiiod of child-beanng, and among men between £^ 
and 2fj. Stature also jiossesses an influence, tall men general -^^ 
being short-lived. 

Geographical position causes a variation in the i'atio of luc^ 
tality, being 1 to 41 in Northern Europe,! to 40-^% in Centra 
£uroi>e, and 1 to 33i"o in Southern Eui-ope. The greate- ^^^ 
number of old ])eople is found in the temperate zone, whic:-^ ^^ ^ 
furnishes also the largest proportion of recorded instances ci— ^^' 
longevity, of which the following may be mentioned, as beii 

ell authentirat.'il: ^Martraivt Pivtteii, 1 37 years ; Thomas Pi 
152; Jolni Il.K^m, ITii ; P.-tcr Torton, 185. 

The fullnwiiig tables show the proportion of persons in 
ferent communities that reach the age of 100 years, and ; 
the average mortality in some of the great cities ; 

Nntnber whn are tOO mid upward in n popalntion or S0,000 : 

En^lnnd O'Sl 

Wnlc* 0-fiO 

United Sim e^ fVce men 1-03 

•' bIhtcs 14-10 

When diws tlio <ii)«llcntiDl power bcpin to decay? Do the inprcuioM of ihe osriieri^ 
la Mrr period uflifv fndBfini? What is iha avcrnm duration of huroitn lireF At nliai fcitf 
oil i» llie mortaliiy gri-niesi? Whnl proponinn of binbs are tost nt tlii! cIok of iho flr^ 
year? Whnt at llii< «iiirh— the fiftecmh— iwenty-flftli? Wliat diffi^rctica cxiu in the mi- 
of mortaliiy in llie different iciics 7 What n llie influi>nce of ttuinrc on ilio rate of monalff 

' What is tlic inllucnca orgtogntpliicalpoBiiian? Itkniion tome of llie inBiaocv* of th -* 

ilcBt longcvilv. 




TIIE APPROArn OF DE,iTn. 





MorliUlyonBla 


















Viennn 


23 



MqiUIIIt onx bi 

England 51 

■W«lci UM 

Pliiladelphia 4G 

Hancbrater 44 

I/ondnn *0 

New York- 88 

The longest life must at last terminate, and eveiy one mm 
sooner or later pass over the bniJt^e of death to join his fori 
fathers in the unknown laud. We instinctively shrink froi 
the final aet, and speak of it as the agony, ilreadlng It uot 
niueh on aeeount of the pain suffered as of the gloom and i 
lemuity of the grave, and the uncertainty attending our fate 
the night of eternity. 

Death rarely comes to us by the slow appi-ooches of old 
his on^ilaught is sometimes'sudden, and life ia overwhelmed 
fore the approach of danger is even suspected. lu such a \'i) 
lent, su<Iden physical annihilation there can be but little 
for the face of the soldier who has been cut down in a nic 
bears the expression that was flitting across it at the time tl 
fatal bidlet touched the vital spot, and retains even in deal 
the impress of the exultation of victoi-y or the despair of ' 
feat. 

Excepting the corapai-ntively small niunber of instances 
death by accident and old age, we may regard it as usually 
curring from disease, whicli i3 more or less prolonged, so that 
the lowers of life are wasted, and sensations and senses dimmed 
before dissolution commences. The approaching tei-mination 
of tlie sufferings of the dying man have been so well portrayed 
by the pen ot Hippocrates that even niotlem science accepts 
his description as being unsurpassed, and gives to the peculiai' 
jihysiognoniy of death the designation of the " Facies Hippo- 
cratica^' It is ushered in "by the patient showing a disjwsi- 
tion to lie on his back, his arms stretched out, his legs hanging 
down, and a tendency to slide down in tlie bed. The motions 
of the hands are sometimes uncertain, and the patient picks at 
the bedclothes as though he was attempting to remove small 
objects from them ; the countenance is changed ; the lips hang 
relaxed and cold; light becomes unbearable; the bnghtnees 
of the eyes is lost, and they become ovei-spread with a misty 

tud ; tlie balls shrink into their sockets ; the nose is sharpt 

le of the greater mortnliiy □fKew York is ihc cnonnous nambcr of cmigri 
It ihnt port. 




I 



Hl8' 



TISSUES AKE HEPAUtED DURING SLEEP. 



I 



ened; temples hollow; eai-s cold and white; and the fsatL-^''^ 
pinched, ami of a greeuish or lead-colored hue." 

Though death is generally regarded inth such intense f^Sw- 
ings of I'epugnauce, it is nevertheless essential to the well — ■"** 
iug of all living creatures, tor the processes of life can not^:^ "^ 
accomplished without the continual destruction of the tiss-^*''^^ 
composing the body. To these phenomena the desiEmation -* "' 
interstitial death has been given- it conmiences with tlie£?^f** 
breath and continues througliout life, but is repaired by the "J"' 
gans of nutntion as fast as it occurs. During tlie early peric:^:^* , 
of life repair is more rapid than waste; the body consetpien^^'^v 
increases in size and weight, until finally an equilibrium 
reached, which lasts for a few years, Avhen the weight co^ 
niencea to decline, the waste beiug more rapid than the rep* 
in the systems of old people. 

Iiep.T.ration of tissues takes place cliiefly during sleep. In ■ 
fancy and adolescence, when the body is growing i-apidly. t^^ " 
greatest portion of our time is spent in sleeping, so that tt_^ 
construction and increase of tissues may advance with as litt^ 
interruption as jiossible. When the adult period is reache* 
the average amount of sleep is about eight hours in ever 
tiventy-four, though many people need only four or five, o 
even less. As old age apjiroaches, and the recuperative pow 
el's of the system decline, a far gieater amount of sleej) is i 
quired. 

The approach of sleep is marked by the gradual loss of vis 
ion, then the sense of smell is blunted, heanng becomes uiortf 
and more obtuse, the sense of touch is obscured, the mustie* 
are relaxed, and the pulsations of the heart and the respimtorji^ 
movements become less rapid and more I'egiUar. Tlie deeped 
sleep is in the earliest jfart of the night, and it gradually be- 
comes lighter on the approach of day, when the mind regaim 
its conseiousness iu the reverse order to that in which it was 
lost. I 

When the system does not obtain a sufficient amount of 
sleep, either on account of care, anxiety, or ovenv(»rk, the greats- 
lien'ous ganglia l)ecome irregular in their action, the ftinction^ 
of the body are disonlered, digestion is imperfect, and the ton<y 
of all the organs and tissues steadily declines. But an over- 
indulgence in sleep is almost equally injurious, for the nervoiw 



WliM li imentitiftt dentil? At wh*t l<nio iliics rcpnir take plnci 
lemt Al whnl perind do we sleep meat? What in (he arcrngc 
hj ndulu t Why do old people riccp so imicli ? WI ' ■ 
labrerKd br ihe approach of alerp? At vthat lime is 



•rder in which tlm kiiwi nro 



TUE DISTRIBUTION OF PLANTS. 



system becomes less sensitive, the moral and intellectual facul- 
ties are blunted, ami all the functions of the system are con- 
(luotetl in an imperfect manner, and some even think that eoo- 
tinued over-sleeping will produce such serious diseases as luna- 
cy and idiotcy; but it is probable that in such oases the tend- 
ency to ovei-sleep is merely a symptom of the approach of the 
disease. 



LECTURE XXXIX. 

DTFUJENCE OF ESTERNAL AGENTS ON THE PITTSICAL AlTD INTEL- 
LECTl-AL CONDmON OF SIAN. 

DUtribution of Plat>ti>. — Conditions tehich Control their geographical Po- 
aitiuri. — Mature of the lioimdary-liHai formed. — Influence of Ocean Cur- 
rents on Climate, — DUtrilmtion of Animals, — Itiflueiice of I^iygiccU 
jtgentt on Man. — T/ieories rtifartUng the Origin of the JIuman £ace. — 
.^planation of the Production vfltacea, — Variation In tlie Color of Men, 
Measiiremmta of the Hktdt. — The FaciiU Amjk. 



1^ 

flT 



^ It is a well-known fact that different vegetable products 
^■e found on difterent part=i of the eai-th's surtaee. The condi- 
tions which control the distribution of plants are chiefly heat 
and moisture; and, by examining into the causes which influ- 
ence these conditions, we find that there is not a single physical 
HKent that does not possess more or less power in determining 
^Be geographical distribution of every species of plant. 
^Klf we trace on the globe the lines which mark the limits of 
^K>wtli of any plant, we find that they do not follo^v the par- 
Bplela of latitude, but i>ass above and below theiu to an extent 
equal to ten or even twenty degrees. These curves are paitly 
due to the influence of variation in elevation of the surface 
above the level of the sea, but chiefly to winds and the cur- 
rents in the oceans, which a)nvey enormous masses of warm 
water from tropical to northern regions, and modify the temper- 
ature to such an extent as to produce a climate milder than that 
"other countries which are much farther south, but do not 
the same advantages. 
le conditions which influence the distribution of plants 
determine that of animals, confining them to certain local- 
is, beyond the boundaries of which tlieycan not pass but at 

-0 the ran Jiiians tlmt contml llie dintribiition of pUnis ? What is the nntare of 
E lines llint bonQil the (listribntian orrnrions iilnnts? Whnt nro the agents ihat praJuco 
— » 'low do ihc ocean currents mtxlifj climute? 



I 



INFLUESCE OF PHYSICAL AGE^"^S ON MAN. 

the risk of destiiiction fi-om various pLysical agents. Certain 
species are more widely scattered tuan others; bat they ^^« 
few ill number, and are almost all inchided iu the list ofc»r~e* 
tures which are domesticated by man, either for ])urjK»8es «t 
pleasure or profit. 

As physical agents determine the characteristics and di:^^=ln- 
bution of plants and animals, so also tbey influence the pf^— nil- 
iarities and distribution of man, changing the tint of his y^Wiiu, 
altering the shape of his skull and features, and influencing fe 
habits and mental qualities to such an extent as to prodnt^^^ " 
number of races that dlfler so widely in their characteristic^^ «^ 
to have given origin to the doctrine that all men have not h ^en 
producecT from one original pair, but that there have bee»i"^ * 
number of different points of origination cori'esponding to *be 
different races or types of men. 

The two theories of the Unity and the Diversity of Oit^2[,'*'' 
have numerous and influential supporters among the highest **"' 
tellects, Ijut the majority of savants accept the doctrine of t- *^* 
unity of the race, which is by far the most natural ami [»ro'B'- 
ble, explaining the differences that exist by demonstrating tL* 
they are produced by the action of external physical agents. 

One of the most striking differences is the variation iu t- ^ 
color of the skin, that of the inhabitants of tropical regions W - 
ing olive-colored or black, while, as we pass northward, it t^-~- 
eomes lighter, until finally, in the tenipei'ate regions, it is whi '^ 
or of a ])ale pink tint. The best illustration of the influei«- 
of temperature on color is afforded by the Jews, who, thon^^^i^. 
scattered among all the nations of the earth, have jn-esen"^^— ' 
their national type intact by continuing to intennarry amo*^ — .° 
themselves; yet their color varies with the locality they inh»-r" n 
it, some being as white as the pm-e-blooded Caucasian, ^*'lj^^;^_^.i 
others, whose ancestors have lived in tropical climates for nac^^^^^-^^i 
centuries, are dark, but preserve the Jewish featui-es unaltei-e^^;^ 

The change in color of a race requires many generations t— '^^ 
its accomplishment, but there are other characteristics of t^^ 
difi'erent types ■« hich are more profound in their nature, t:^-^^^^, 
therefore necessitate the lapse of a far longer period of tiiE ^---_„ 
to affect them; among these are the peculiarities in the figti^^^^^ 
of the skull, and variations in the size of the cranial c«\-ity ai*^^__ 



widely disirihuied ? la msn inlgeet in tlic inHnenre 
e tho two thvoricB rei-Brding Ihc oriinn of ll>u liuman r«c 
'circd? How dues the ihi-ory of the nnily explnin ilie 

_, . Imtmiion of clmnge in rulor iluo lo cxlcrnal pbysjcal 

Wh*t other chnriurleriBlice of rRce exlat besidei color 7 



?Vhi 



Whni species of animnU ni 
icBl HBcnts? Whnt a 
:h t» nimii gpnernlly rt 




SIEASUKEMENT OF SKULLS. J 

n, U'liicli deterniiiie, to a certain extent, the iutellectual 

rw. 

kuUs are ineaBiired by two methods, one of which consists 

Uing the cranial cavity with shot or peas, and pounng the 

bents into a measuring glass, while the other is the determ- 

Sou of thf^ facial angle. This is performed by dra\viiig two 

one ti'om the meatus auditorius extermis to the base of 
nasal cavity, where it meets another drawn along tlie me- 

line from the forehead to the eame point ; the angle in- 
led between these two straight lines is called the facial 
h. 
?ie variations in this angle are shown in the adjoining fig- 

of skulls. In the highest types it is over 90°, while m 
negro it falls sometimes as low as 70°, approaching to tliat 
le monkey, in which the facial angle measures 50° in some 
lie higher species. 




186 DIVISIONS OF NATIONAL LIFE. 

Though a v^ery considerable period of time is required in 
der to influence the configuration of the skull, we find tl^sit 
when the highest race is subjected for ages to debasing in Ali- 
enees the type of the skull gradually changes, the chin becoi:E"i^s 
more prognathous, the intellect is lower, and all the ener«_f;i^s 
are spent in obtaining food and in the gratification of the ^xxiL 
mal propensities. 

As the life of an individual is marked by periods of de ^' el. 
opment and decline, so also the lives of nations or other col 1 emo- 
tions of men show the same phenomena of gradual growtl :i in 
power and intellectuality until they reach a maximum, wliicli 
IS maintained for a certain period, after which a decline sets^ in, 
and sooner or later the nation dies of old age. 

What conditions change the facial angle ? What is the coarse' of life of a nation? 




IITGIENE OP FOOD. 



^ieisi&na of Hygiene. — Conditions e»gential to a lieaUhy State of t/ie Di- 
gralive Apparatus. — Kumber of Meal» per Diem, and the 7'imes at tckich 
tliey should be taken. — Adaptation of Pood to the Age of the Individual. 
— Varieties of Milk.— -Food of Injantt.— Influence of the Diet of the 
Mother on the Character of her Milk. — Selection of a Nvrae. — Frangi- 
pane. — Duller. — Cheese. — Age at ahich solid Food should be givai to a 



HroiESE may be studied in I'egard to its applications to the 
'unctions of^lst, Digestion; 2d. Respiration ; 3d, The skin; 4th. 
Vliiscular, nervous, and osseous tissues ; aud, oth. Prophylactics 
Lnd quarantine. 

The first aud most important condition to be observed in 
Ceepiug the digestive organs in a healthy state is regularity in 
lU the acts connected with them. The time at which the 
kieals are taken should be as nearly as possible at the same 
jour each day. Three meals a day are sufficient for the ordi- 
nary wants of adults ; the first, called breakfast, should, as its 
lame signifies, be small in quantity, while the chief meal of the 
lay shoidd be taken in the afternoon, to supply the materials 
»ut of which the tissues of the body may be renovated during 
.he night. 

In his excellent work, Erasmus Wilson draws particular at- 
tention to the influence of diet. He maintains that the proper 
"eg^ilation of the meals is, breakfast at 8 or 9 ; lunch at 1 or 
S, with a Clip of tea or coffee ; and dinner at G or 7. This ar- 
rangement allows an inteiTal of five hours between each meal ; 
xnil, since the stomach requires on an average three hours for 
tlie digestion of an ordinary meal, it is allowed two hours rest,' 



Whnt are iho dirisiotiii of h_vi;ipn 
the iliBP'tivc nppnnniM ? How m 
ihonld Iho meals tw lakcn? Wlmi 



' \Vbni is the cssentUt coTKlition for pctfcct liealMi of 
pf men!- n Jay cbonld niliilw infcc? At "hnt limo 
( rlie advunloge of iho nrrangemenl suggcslcU bj WJI- 



188 AEHAHGEllEXT OF THE 3IEALS. 

which is necessary in order that it should perform its work in , 
a satisfactory manner. The habit of eating between meals is , 
most reprehensible, its certain result being a loss of natural ap- 
petite, dyspepsia, and a numerous train of aeconipaiiyiiig evik 
In regard to this habit Wilson says : " The stomach is a patient 
drudge, but tease it not, fi'et it not, if you would keep it in a 
good humor, and \7itb0ut ita good humor, alas foryoura" The 
great argument in favor of se\en o'clock as the dinnerhour i«, 
that nearly all men have finished their daily occupations at 
that time, and are ready to dismiss the " wliop," together mth 
the cares and annoyances of business, and,donning their''(le- 
cent black," assume the human condition again, in which tliey 
can enjoy the pleasures of the table and fireside without the 
fear of some summons to business, which, by diverting tlie 
blood fi-om the stomach to other organs, is opt to cause dye- 
pepsia. 

The above may be regai-ded as the most philosophical ar- 
rangement of the meals, and the majority of men follow it more 
or less closely, though the occupations of some, as physicians, 
often iutei-fere with the rigorous adoption of any system, hi 
the savi^ state there is perhaps the greatest irregularity, for 
the tbod is to be obtained by hunting, which Is always uncer 
tain in its fortune, and a savage is proverbially improvident, 
consequently he may often pass days without procuring a suf- 
ficient supply, and then gorge himself to repletion when ojipf 
tunity oftei-s. The result of such a system is the reduction of 
man to the level of a mere animal, for savages, as they arejiB*' 
ly called, make the obtaining of tbod the chief object of tieir 
lives, 

A proper adaptation of the food to the age and oocupatioDis 
also of very great importance. Articles which agree perfeftly 
with an a<lult are ahnost poisonous to an infant, while a con- 
tinuous diet of milk woidd try the powers of an adult severelT- 

It needs no argument to convince us that while milk is still 
fresh and pure it contains all the kinds of food necessary "" 
the healthy maintenance of a baby. From cream the infuot 
obtains material wherewith to clothe itself with a jacket of f*^' 
Fi-om curd it makes muscle, which, though at first soft.aft^'"* 
while becomes finu under the influence of almost ceasele*' 
motion. In whey, which is made up of water, sugar, and f* 
rioiia salts, it iinds fuel wherewith to keep its bmly waroi.au^ 

Stioaki font] lie eaten belireen meal*? Wliat ii iho aJrialBga of a IbM dJanerJi"'''' 
Haj* b11 aitidei of ruoil be oseil iniUicrimtiuiet* «I bH timet? 



CHANGES IS MILK. 



189 



lineral matter with which to consolidate its bones and pre- 
nre tlie foundatlnii for a healthy, vigomus body. 

Though presenting every kind of food required by the hu- 
laii system for its proper maintenance, milk is prone to undergo 
>ri<iiis changes in its character ; tlierefore, it sliould always lie 
iven to an infant while as fresh as possible, for if it stands for 
time it becomes almost a poison. Set aside a small portion 
n- a few hours, and that which was sweet in taste and pleasant 
I odor will be found sour and untVagrant. The constituent 
hich gave it riclmess has risen to the suiface ; it is the cream, 
elow this a thickened substance has accumulated, known aa 
ird; and finally, a watery fluid has separatt^d, wliich is the 
iiey. How curious that nature should Iiy her own devicea 
inke an analysis of milk, and show chemists how to proceed 
' they wish to know what it is, of what it consists, and the 
se of each constituent! 

Fresh milk when not properly digested often disagrees with 
ifnnts, and this is not to be wondered at when we reflect that 
;3 teruientation evolves an acid which will dissolve many min- 
rals by virtue of its corrosive property. In its fresh state ndlk 
oritains a sugar, called, trom its speciid charactcristice, "sugar 
f milk ;" it is not sweet, as other sugars, and readily changes, 
iider the influence of a ferment, into what chemists call " Lac- 
ic acid," or " acid of milk." The result of this fermentation is 
he cause very often of the cries and lamentations which give 
inny suffering babies bad reputations. 

Tlie milk which, according to the old nurse phrase, "baby 
irings to this world with him," is by far Ins best food, pro- 
idea it is abundant in quantity and good in quality. This 
ailing, the milk ^vhich is most suitable is that of the patient 
nd much enduiing creature, the ass. 

Ass's tuilk, however, is not easily obtained, so baby is dnven 
o the use of cow's milk, which, though ditiering somewhat from 
vouian's milk, may, nevertheless, be made a capital substitute 
>y a little doctoring, according to the age of the intended i-e- 
ipleut. Though analyses differ greatly, an excellent aut]iority 
m such matters gives the following contrast between woman's 
ailk and that of the cow. One thousand parts of each contain 
he following proportions of each ingredient: 



WOMAN S 


MILK 


AND 


COWS MILK. 

WDinin'i milk. Can's m 


























SaItR,eU:. 






M.I fl.S 



"We here see that woman's milk contains only six parts of 
ebeese, while cow's milk fiirnighes twenty -eight ; in other worfs, 
cow's milk is nearly five times stronger in muscle-making food. 
It is. therefore, simple common-sense, that if infants are to lie 
fed upon cow's milk, it must be dihited with five times its bulk 
of water to give it a strength, or rather weakness, similar to 
that of their natural food. 

"We should hardly expect to find cow's milk so inferior in 
SM'eetuess to other kinds as the table shows, and still less lo 
discover that, if made similav in certain other i-espects to 
woman's milk, it should only have one eighth of its Bwet'tnes& 
Seiions as this dift'eience is, it is unimportant, being eaaly r** 
tified by adding enough sugar to make the diluted cow's milk 
sweet to the taste. 

Though cow's milk is richer in fat than woman's milk, hy 
the act of dilution tiie proportion is reduced to less than one 
half. This is In part remedied by the sugar added in tba 
sweetening process descnbed iibove. To render milk swwl to 
the taste more than the normal proportion of sugar in wonian'a 
milk is present. This excess of sugar is converted in the boJy 
of the infant into fat, and so the diminution in butter is not 
felt when prepared milk is properly sweetened. 

In cow's mdk the salts are already in smaller proportion 
than in woman's milk. By dilution this inferiority becoineS 
five times greater. Hei-e, then, is the cliief fault iu preparing 
cow's milk for infants. Something should be done to make up 
this deficiency in salts, and especially in phosphates, whicli aw 
so essential to the construction of a properly nourished hotly- 

The necessity of securing a supply of pure milk is ui^ent. 
Accurate determination of tlie question of puiity can only ^^ 
arrived at by an analysis, but as this is in the majority of ca*** 
impracticable, various instruments have been devised by wliicoi 
in a few moments, a proximate estimate of i ts character may h« 
obtained, particularly ns regards addition of water, which is ^^ 
tisual adulteration. 

Whrit ui'D (lie chief ilirfcrenocB lielweeti cow's milk nnil womnii's mitk ? Ilun slioiilJ "'*]' 
milk be prepared 0.4 n nubsiiiiiiB Tor nomnn'a milk? How inaj (he deflcwaqf in hS*' '*' 
ootrecled? Wbal is llie usual aduUerftUan ? 



r 



ITIE LACTOMETEK AND CEE-VJI TUBE. 



The first of these instrumenta is the lactometer, repre- 
sented in the ailjoioing figure. It consists of a long, 
lioUow cylinder of glass, h, which acts as a float ; this is 
liallasted by shot placed in a bulb, a, in order to iosure 
an erect position when the apparatus is placed in wa- 
ter or other fluid. From the upper part of the float a 
stem, c, rises, which bears in its interior a slip of pa- 
per upon which a scale is ruled, Tlie jmnciple upon 
which this instrument acts is, that if placed in water 
it sinks to a certain point which is marked as the zero 
of tlie scale in the stem. If it is then placed in a fluid n^cijui™ 
heavier than water it floats higher, and a Itmger part of 
the stem projects above the level of the fluid. According as 
a longer or a shorter portion of the stem projects above this , 
level we know that the fluid is heavier or lighter. The scale | 
is so arranged that when the apparatus is placed in good,fi-esh 
milk it indicates a value of 100. If water is added fo the milk 
the instrument sinks deeper in tlie mixture, a lowei" value is 
obtained, and thus the adulteratiou is detected. 

From the description given it would seem that the action of 
the lactometer would be as reliable as the instrument is simple, 
nnd so it is, when properly and fairly used, but this is not 
always the case, as may be readily shown. 

When perfectly fiesli, milk consists, as we have seen, of water 
containing vai-ious substances in solution and suspension, among 
\s'iiich is fat, or cream. Fats, as we know, are lighter than 
ivater, and by virtue of their presence the fluid is lighter than 
:he quantity of various solids present would lead us to suspect. 
When this fat nses and is removed as cream, the remaining 
iquid becomes heavier, and so the lactometer indicates a higher 
Tavity in skimmed milk than in that from which the cream 
las not risen, An unjust salesman can restore to skimmed 
lilk the original lightness by merely adding a little water, 
bus causing the lactometer to "ive the same reading as when 
daced in perfectly fresh, unadulterated milk. 

Another device is called the ci-eam tube. It is a tube of 
onvenient length and diameter, closed at one end, ayd bear- 
ng a scale showing divisions into one hundred parts, zei'o being I 
leftr the open end. Milk to be examined is poured into this 
ube until the zero is reached ; the instrument is then set aside 
n ft vertical position for twenty-four hours, or until cream has 

How mny tlie luciometer give faUa reaulta? Describe ihc ci 



192 



THE PIOSCOP. 



risen. The amount of the latter is then read off on tbe scale, 
and an estimate of tbe richness of tbe milk obtained. Aver- 
age milk, when thus examined, gives from ten to fourteen |iam 
of cream. One objection to this method is the time requireJ 
to obtain a result; this has been recently remedied by placing 
the tube containing milk in a whirling apparatus, and suWit- 
ting it to centrifugal action. Under this influence separntioa 
of tile cream from milk is accomplished at once, and it only w- 
mains to read off tht? result. So prompt is the action of tliis 
arrangement thiit it cannot be long befoVe it will be ailojilMi 
on lai'ge butter farms tV>r separation of cream on a threat sate. 
Whde fat remains in suspension in milk it gives it a certaiu 
tint when it is examined in a thin layer. This is lost or 
changed when the fat is removed. Various modificatious "f 
this principle have beeu devised, anion" which is one recently 
iutrodnced, called the "Pioscop," whifb is 
rejiresented in the adjoining figure. 

The apparatus consists of a round disc 
of liard rubber, a, 2i inches in diameter, 
slightly raised to%vard3 the middle, with s 
shallow, dish-like depression in tbe cHitre. 
Into this depression a little milk is drojiiwtl. 
Tbe rubber vessel is then covered liy a glass 
disc, b, of the same diameter, transparent iu 
tbe middle; the riia of this is colored by^i^: 
iiidial strips of paint, varying from wliite 
to dark gray, and marked with the qniiliiy 
corresponding to it, from cream to veiypo""" 
milk. 

Tbe color of the thin layer of milk, as see" 
Tin- ri.™.i.. thrcngli the transparent part of t!ie gla** 

plate, corresponds with one of the sis color-strips, and thus its 
quality is determined at a dance. 

It often happens that good milk can not bs obtained. In this 
case, condensed milk offers a fair substitute. It is prepared ^"S 
adding white su^ar to milk in the proportion of one ounce to 
the pint; the fluid is then concentrated to one fifth in vacnu™ 
pans, and preserved in se.iled cans. When opened, tbn ^^^' 
tents of the cans keep better if a little is removed each ""/ 
from tbe top. When used as a substitute for cow's milk- 1' 
should be diluted with four times its volume of watex f^' 

DoKribe the Pitucop. Haw does lUo PiuBcop net? Mow U cuDdeoMd milli yKg^' 
How ahouU Gondenied milk b« propared Tor iahaU' iim7 




r 



INFLUENCE OF DIET ON TnE MILK. 193 



nfjints this should be still furtlier diluted, as in the case of 
row's milk. 

After n while, pnp, made by adding n little flour to milk and 
>oiling the mixture for some tinu', is the most suitable article I 
>f diet. The fluid's system haviug become accustomed to thia, 
he cu.Trscr kiuds of flour sliould be used, if they do not cause 
rritatioii of the digestive iipparatus. Such flour contains a j 
ar^ei' pi'oportion of that part of the seed which is immediately 
instil' the outer skin, and which is very rich in phosphates. 
\.ttention paid to these matters at the proper time during the 
growth of young children would do much to prevent the de- 
orinities so often seen. Finely bolted flour is carefully cleansed , 
i-i>in the exterior portions of the grain, which are richest in • 
iliosphates; to feed an infant on this is to depiive the bones i 
if the mineral matter they need, and so make them soft and 
iable to bend. 

The character of the milk exerts an imjwrtant influence on 
;lie health of the child, extraordinary articles of fwnl, aud med- ! 
cines which have been taken by the mother or nurse, changing 
;be secretion of the mammary gland in such a manner as to 
■eniler it highly deletenous to the child. Familiar illustra- 
tions of this fact are often furnished by cows' milk, when the 
mimal has fed on turnips, wild onions, or other vegetables that j 
possess a markeil flavor. 

Special attention should be paid to the condition of the milk j 
if tne nurse or mother when children are sick, as the malady Is j 
>ften due to the changed state of the secretion. Advantage is I 
iTe«|uently taken of this channel in the administration of raedi- ] 
jines to t'hildren, and it is, as a rule, best to introduce the med- | 
icine into the system of the child by giving it to the nurse, and ] 
so impregnating the milk with the desired properties. 

T!ie choice of a nurse i.s a matter which pai-euts often disre- ' 
winl or pass over lightlj-, yet it is most important as regai-ds 
the future ^velfare of the child, for it is well knomi that certain 
njeinfic diseases may be in this manner communicated to the 
cnild, and there is but little doubt that some hereditary dis- 
ea.se^, as consumption, may likewise be transmitted from the i 
nurse to the child. Some writei-s even consider that traits of 
character, such as temper, may also be communicated through 
this channel, but it is a statement to be received with consider- 



t 



pnp prepnroil? Does iho diet of the mm 
milk f How rnny meJIciiies be HdminisIereJ U 
lUiiicoted tlii-ough tlieniilk afitie nanc? 

N 



104 



PKEPARATIONS OF SIILK. 



ah\e allowance ; yet, as prevention is iih\'ay8 better than aire, 
it is wise, in making a choice of a nui'se, not only to takeinlo 
consideration her own physical liealtli, but also to pay some At- 
tention to any hereditarj' taint that may exist, and also to ex- 
amine into her mental peculiai-ities. Aa illustrations of the 
prevalence of these opinions even in remote times, we msv 
iHiote the Roman fable that the ferocity of Romulus was due 
to his having; been suckled by a she wolf, while the ajuoroas- 
jiess of Jupiter was caused by his having been fed chitfly oa 
goats' milk. 

Milk, though well adapted to the wants of children, ofto 
disagrees with adults, producing severe dyspepsia. Whpii it 'v 
desired to employ it in spite of this objection, we may takend- 
vantage of the tendency of the fluid to separate spintaneou!'!)' 
into tnree constituents, liz., cnam, curd, w//et/, and by adniinis- 
tenng the cream and whey, avoid the disagreealile synipt<rtii» 
Avhich are nearly alwajs produced by the cui-d. ivhich confl;o- 
lates in the stomach, and either passes through the iiitestine 
unchanged, or is ejected by vomiting. It is often the case tlist 
' wlien milk is boiled it vnW agi-ee perfectly; the addition of » 
little salt produces the same i-esult. 

An excellent preparation of milk, caWed franffipane, is forro- 
ed by evaporating it to diyness, and. adding pulverized al- 
monds aud sugar ; it is highly nutritious, and is given with »i- 
vantage to patients suffering with phtjiisis or consumption- 
Butter is of itself very digestible, but wlicn melted it iicdeJ* 
goes change, and is of^en highly indigestible. Cheese is very 
indigestible, and this property is inci'eased by ctjoking, the 
"Welsh rai-ebit being one of the most iimnanageable and ri'liel* 
lioua substances that can be introduced into the stomach. Sow" 
varieties of cheese prepared in Germany, and that made m 
Cheshire, in England, occasionally pt-oduce symptoms of poi* 
oiling. 

Tlie appearance of the teeth indicates the necessitj' of nHX^J" 
fj-ing the diet; more substantial ailicles may now be grodnal- 
ly added, such as ^vell-cooked bread i\'hich is at least ft <l*y 
old, portions of beef and other digestible meats, and a mwl'*' 
ate supjtly of fresh fi-uit. The quantity taken at each loeol ^ 



Wliat poinli sho'il J he ntlcnded to in the chincc of a n-i 
»grco wilh nn ndpll, whkh n>n»tituenlt may be lacd with 
olilnincd? What in iho cff«-l of boiiini; on milk? What 
tret of cDKkinBoii Ibc iligisiiliili'j of bullet? Whi 
" ■ ivinriioniii * 



o lako solid ftRMl T Wlial lutMAlirc* ihould l« selected t 



i^l-nnrao? When millnto* ^ 

impnniiT, and bow nwy lUfj* 

w rranpmno ? Wliat !• ^^V" 

s efftpl on cWw 7 Wlwf nJ*** 

Al nh "~ 



r 



KFFECT OF DIET ON THE RATE OF MOUTALITY. 



a child should be small, and the meala should be administered 
more fi-equently than to an adult, for the wants of the system 

Kthis period of lil'e are veiy urgent, and four moderate meoIaJ 
lay will give better health than three. I 

In cities, the gi-eat mortality \vhich exists among children iu 
the summer season is chiefly due to the careless manner iu 
which they are allowed to devour all kinds of uiiiipe and halt- 
decayed fmit and vegetables. Among the children of those in 
afilaent circumstances an iuimenae amount of evil is produced 
Ijy then- absurd and criminal imlulgence at the tables of their 
pareutu in such articles as pork, lobster salad, new potatoes, 
stale fruits from the city stalls, cake, and pickles, being indi- 
vidually capable of giving any child a diarrhcea, and yet we, 
often see them all administered at one meal by an indulgent 
parent, when tlie child should be iu the nui'sery partaking of _ 
pap, with a little meat and bread, if it is desii'ed to have it J 
w up into a healthy atlult. 



LECTURE XLI. 



ANIMAL FOOD. 



tdiliotu that produce Scu?vy. — Preeention of Scurvy. — Hxtraordinari/ i 
hrticlea empioyed as Food by the Aneicttts and Moderna. — Peculiaritiet J 
ftheFiesli of yintnff AniinaU, — F^ct of the Food on the Fieeh o/an I 

mmal. — Efnnt of Season. — The Mtmet. — Aj/e at which the Ox and 1 

*i«s/> reach "Perfect !<m. — ^ect of Castration w* the Flesh of A n imaU. — 1 
Oritive Properties of lean mid fat Meat. — Proper TXme and Method of I 
sughtering. — Nutritive Qualities of the F7em of Birds. — Castration I 
ftd Cramming of Birds. — ^eet of Cooking on the Digestibility ofR^gs. I 
'^Poisoning by unieAotesoine Flesh. — /VhA iind lieptilea used as Food. \ 

t~Caviare.— Tfie Oyster and other ShellfUh. 

iiouoii the teeth of man show that he is omnivorous, there ' 

are many tribes that live in northern regions that subsist en- 
tirely on animal food, all vegetable supplies failing in exti-eme 
northern climates. In the tomd zone, on the contrarj', animal 
food is not employed, and it is only in the temperate parts of , 
the earth that man can be strictly said to l»e omnivorous. I 
When the system has once been accustomed to the use of a I 
mixed diet of both animal and vegetable substances, a total | 
abstinence from either is very apt to produce a diseased condi- 

BiiU n iTbj- nhoulii be civen to n chilJ ? Whnt n ilic chiof tausa of ilie i 



t 



196 EXTRAORDINARY ARTICLES USED AS FOOD. 

tionofthesystein, to which tlie name of scuiry 19 given. It is a 
very common error to suppose that Bcur\'y is always due to the 
(.•outiiiueil absence of vegetable food, but the long-contiuiied b1> 
stinencc fiora animal food will produce the same result. Tie 
vast majority of cases', however, occiir on ships and in armies in 
which there is a want of a auffieieut supply of vegetable mb- 
stances. The pi'oper method ibr avoiding the disease is to 
furuisli the missing ingredient, or to allow a regidar ration of 
lemons or some vegetable acid, such aa vinegai'. The nnHii^rn 
system of jjreserviug vegetables by hermetically scaling tlifm 
has obviated all necessity for the existence of this disease, ani 
it will doubtless, iu future, be almost unknown in navies, when 
it is BO much to the interest of governments to preserve Ibe 
health and efficiency of their sailors. 

All parts of animals exct^pting some of the secretions, are or 
have been employed as food. Among the ancient Romans, tli« 
brains oftlie ostrich and peacock, and tongues of nightingales and 
other singing-birds, were much sought after. Some of their disii- 
es required more than one hundred letters to write their naiues- 

They were also very fuutl of tbe flesh of the young ass; nnd 
young fat puppies were a great dainty in Coreica. At tlie 
present time the civilized disciple of Kpicurus in our own coun- 
try regards tlie trail of the woodcock as the bonne botic/ie orbis 
most luxurious dinner. Disraeli says, tbe cooks of the ancients 
who appear to have been hired for a grand dinner, carrieil tlieir 
art to the most whimsical perfection. They were so dexterous 
as to be able to serve up a whole pig, boiled on one aide, and 
roasted on the other. 

Among the cxtraordinai-y substances eninloyed as fooJ W 
may cite the instance of the quaiTymen of Thnringia,whoeBt 
a substance called rorh-lntter, which they sjiread on their breoA 
A species of clay is an article of diet among the Ottomaquw 
of South America, and Humboldt states that they devour 
enormous quantities, so that their stomachs are greatly difetenil- 
ed ; he also thinks that they derive some nutiiment fixini it. 
This is not at all improbable, for the clay that is eaten by the 
troglodites of South Carolina is found to be composed, to a 
considerable extent, of animalcules. The amount of nntriroeDt 
that mav exist in substances which are apparently devoid w 
it is well shown by the growth of gold-fish, \vhielj are kept ^ 

What nro ihe condiiion* Ihnt produce senrvr? How mn/BTDrnr beprcTpninlT Ms^J 
some of ihe nnidcs reenrUctI r> luKiiricB bj ihe Romnns Mention wmc of tbe exr*"^' 
nnrv Bubstnncw nl prc«nl cni|>loyci]. 



leii 



EFfECTS OF FOOD AND SEASON ON MEATS, 197 

in a 8mall glohe of water, and, though they are never fed, 
sufficient food fi'om the aniiiialcules in the water, and 
and vegetable ova tailing into it from the circumanil>i- 

3 flesh of young aninnds contains a greater jiroportiou of 
I than that of the adult; it is therefore softer and more 
1 water, though not more digestible, as is shown in the 
ices of veal and lamb, both of which are less digestible 
beef and uiuttou. 

! effect of food on the flesh of animals is shown by the 
character of that of the cavnivoi-a. The nations th.it eat 
esh of such animals generally cause them to subsist on a 
able diet, so as to render tlieir flesh edible. TIic great 
iority of the Vii^inia hams over those made from still-fed 
is in great measui-e due to the fact that the former are 
ed to roam thniugh the forest, and subsist on acorns, chest- 
aud Toots, and are finally fattened ou corn, and uot on 
or household garba^^. 

ny animals are unfit for use as food at certain seasons, 
for esauiple, is not used during the summer, aud the flesh 
I buck is valueless in the rutting period. The flesh of 
animals reaches peifectjijn in the early jiart of the win- 
i Avhich time our tables are so freely sup]ihed with game, 
'i theu in season. The flesli of the females that have 
recently delivered is not fit for urse, being tasteless and 
', .ind not regaining its flavor until some time after the 
of the suckling period. 

") digestibility of all meats is improved by keeping them 
they commence to give evidence of incipient decumposi- 
, irfeats are generally cooked too soon alter the animal is 
L and with us venison and game are the only articles of 
that are allowed to gain their true flavor. lu Great Brit- 
iutton is always hung until its flavor \s pronmniced ; and 
! served at the table of an epicure usually gives un- 
Ocal evidence of having been kept for some time, since it 
3 educated olfactory nen'es to withstand the pertume 
I, to which the euphonious designation of the/«m*( has 
given. It is said that the Siamese cai-rj' this system to 
potest perfection, and consider the decayed egg that con- 
fl chick the special delicacy with which to tempt a guest. 

ike |>ecii11nrit; oflho flrsh or jnimg tinimnlf? Ii tlic tlosh ofyoong <inimnl« ns 
lathnl of those tliaC nra fiill ci'OHn ? Docs tho fooil ur nn animal havo any effi-'Ct 
if Hi>w ilota ilio senHOo iiiHuence ilic flcsli oraniniBls? What U liiu cffoci of 
)&I on ill iliee^libilily? Whnt is ibo fumot? 



198 



AGE AT WinCH CATTI-E anOCLD BE SLAUOIITEKED. 



^ 



In the United States there is not sufficient attention paid to 
the age of the slaughtered animals, our butchers killing rleir 
stock when it is demanded, or when they can obtain it, with- 
()Ut any I'efei'ence to its size, condition, or age. In the London 
markets the ox is regarded as reaching peifectiou at about tht 
seventh year, and the wetJier-niuttdu of Eugland, whicli lias 
earned a world-wide reputation, is not killed till the fiftli _V-ar. 
The eft'ect of t-astratiou on the textme and flavor of meats i* 
veiy singular, that of the neutral or castmted animal being fer 
superior to that of either the entire male or female ; the tit 
also is more evenly distributed, and the meat has a higlitr nu- 
tritious power, since it is said that one ounce of fat meat will 
furnish an amount of nutriment equal to that obtained from 
four ounces of lean meat. 

Before )>eiiig slaughtered, animala should be kept ^vithlIUt 
foi.)d ; for, if the gastiic juice is being seereted rajudlj- at tie 
time of death, it is apt to perforate the stomach, and indiifc 
changes in the flavor of the flesh. These eftects are more fre- 
quently found in fowls than any other article offered for sale in 
our markets, the object being to increase the weight of the liitd. 
All poultry with a distended crop or craw should therefore ln" 
avoided, for the flesh is very apt to possess a dieaareeable flavor. 

It was the custom at one time to bleed animals to death 
sloivly, and killing animals by the chase is still thought to w.- 
pmve the quality of game. In some of the receipts in the ct^k' 
eiy books of past times we find such directions as the fcllovc- 
ing: "To wake a pig tusf-e like a iriy, hoar. — Boil together in 
viuegai" and water some rosemary, th^nie, sweet bn-sil, bay 
leaves, and sage ; then take a living pig, make him swallow tlie 
above drink, and whiji him to death, and roast him immtNliate- 
ly." It is supposed by many tljnt the vinegar in the pretw 
ing prepai-ation softened the muscular tissues, and rendered it 
more digestible. It is said that the jiroper way to kill a beflj-* 
hog is for two men to take 1dm by the legs, and nib his \'^^ 
backward and forward o\er snme har<I siiljstaiiee like a ^oW 
until it ceases to squeid, and then cut his throat. 

The method of slaughtering now adojited in ci^dlized coUB' 
tries is either to cut the throat, or, in the large animals, ^ 

At whiit yent docs Ihc ox reach perrcFtion ! M nhnt age should muTlon b« kUk" 
What is iho cffoet of caiimiiun on tho fltsh of aniinokt Whni is tlie relniiro t""*^ 
pDTcr of lean and fat mcnt? Whm a ilic <>l>jc(Tiioii ro Elaiiphicring snimnlt immodiri"^ 
iificr outing? Whni i* iIioheIh to l>o ilio offi'ct of ailminiBicrin(( Ttnr(!ar lo na *«K"" 
itbnnt to be siuiighiorud ? Wiini U the tnctliod of (laagliicnnB ailoptcd in ciTillKd coO" 




r 



EFFECT OF CASTRATION ON FLESH. 



knock them on the head, and then cut their thmats as quickly 
as possible, tliat the blood may flow out of the body. In the 
F]*ench abattoirs they then beat tlie slaughtered animal with 
stave?, and inject air into the cellular tissue by means of a suit- 
able foi-ciug apparatus, ^vhieh operation greatly improves the 
aj»T)earaut:e of tlie meat, 

f he llesh of liirds whose meat is dark is much more nutri- 
tious than that of the white-fleshed birds ; and Stark states that ' 
in the seiies of experiments he undertook on diet, he found that 
he was more vigorous wlieu he ate roast goose tJian any other 
article, but that may have been in part due to the brandy 
which lie in'f)babl)' took as a " pejjtic pei'snader," as it has been 
quaintly teimed. 

Castration has the same effect on biiils as on animals, ren- 
dering their flesh more palatable and delicate, a crammed aijion | 
or yw "/(/;■(/ being one of the most highly-esteemed of modem j 
dishes. It is said that the Kouians blinded the fowls that ' 
wei-e to be crammed, to insure their lieing in the dark. Tlie 
method of cramming at present employed is to keep the fowl 
in a dark warm place, and force do^vn their throats every hour 
a paste made of liarley meal, molasses, snet, and milk. In a 
couple of weeks the operation is finished, but if continued lon- 
ger tlie creature is liable to au attack of fever, and is then un- 
fit for use. 

The digestibility of eggs depends on the manner in which J 
they are cooked, tiyina being the worst method, as is shotVn by " 
the table page 59. The French WTiters on cookeiy mention 
nioi-e than COO preparations of eggs, but of these the most di- 
gestible is that in which they are boiled soft, in which state 
^ey are slightly laxative, while by all the other methods they 

'brenilered more or less constipating. I 

The flesh of animals that have died from natunil causes is " 
rsally known to be imhealthy, and numerous instances of 
death from the u.se of such fond are recorded. As an illustra^ 
tioii, we furnish a case i'rma tlie Lomlon M,ilii-al TieptMtory, 
which states that in \h'2(i a family on the Galloway coast ate a i 
ste^v made of the meat of a dead calf. They all suffered with 1 
violent pain, pui^ing, vomiting, and, when aroused fi-om the ' 
stujior into which they quickly fell, tlie countenance assumed a 
wild e.'cpression ; one died in about si.v houi-s, but the rest 

WhHii-InriK I'f birilt fiiriiMhes llie nin<Lniilnlinii9 flesh? VVIint is tlic cffecl oTcnatrnlicm on 
~ «h nrhirda? Whnt ic tncant by crnmmrn;:, nntl hovi 19 it romtuclcd? Hoir does ilia 
d oTcoofciDK infliicnre ilie Jigcaiibi1it7 of eggs? !• Ilii> flrEili of □Dimnli iliatbavciliKl 
le lit for neaf Wliat arc Ihc Kymptomi [iroiluccd by eating unwliolesomo flesb? 




200 USE OF KEPTILES AND FISH AS FOOD. 

eventually recovered. The stew had a nauseous smell and a 
V)lack color. In his work on Poisons, Dr. Chriatison cites « 
case of a family tLat partook of broth made fitini beef whii'^ 
had a black color, and \vbich caused symptoms similar to th**"; 
described above, and which he thinks wei-e due to the unsouJW 
state of the meat. 

The articles ^\hich are more apt than any others to prodiw* 
the syuii)tom9 related above are the eausages made of li-^fii 
meat, and blood, and ^vhich are very generally used by Clfr- 
mans. The poison they contain Is very dangerous, and it i3 
said that in the Wiirtembcrg territoiies 234 cases of poisoraioZ 
fi'om this cause were recorded between 1793 and 1S.;7.,. ^ 
which 110 were fatal. 

Bacon, and all cui'ed meats, together with cheese and nr^i^^ 
have from time to time ftn'nishetl imdoubted cases of poB- ^^l 
ing ^vhen they have undergone change. 

Salted meats are more indigestible than those ^vlilch ^ 
fi'esh, and when dried and salted they are only dissolved t^=^=^' 
gi'eat difficulty liy the gastinc juice. 

The class of reptiles funilshes but few representatives to ^ 
table, but these are hichly prized ; we need only mention ^ 
turtle and fi'og, and all epicures will at once acquiesce in * 
statement. In addition to these, the eggs of many rejitilcs ' 

also used, and some of the Asiatics eat the flesh of certain ^ 

rieties of lizards. 

Fish fonns the piincipal article of diet of many nations, ' 
they are generally a ]xior and miserable class of people, dev—-*'' 
of all ambition, and steeped in poverty and ignorance. 
Jerome gi-avely relates the story that Mhen the exeeutionei-^' 
tempted, by the order of Nero, to bleed Seneca to death^j 
could not find any blood in his veins, because he had livi't^^ 
fish and finiit. 

It is a %"ery common idea that a fish diet renders a jxjp'' ^ 
tion veiT pix)Iific, and the great proijojlion of children fonm^:^' 
China gives support to the opinion. It lias also been M^^' 
that a fish diet is liable to produce leprosy ; at all events, E^— ' 
a well-known fact that a continuons diet of fish is conducivfc^^ 
the production of nearly all skin diseases, and there are m*^^?] 
persons who suffer severely ^vitli herpes, and other paiiifid **-^,'^ 
diseases, if they eat the t^niallest portUm of fish, and es|>ecir^y* 

Wlial si>«Ni|p'» jiriKiiiro riniTlnr •rmpioiiis? Wlini other nnicW of food cauv |*ii'i» ' 
Are Mitcd mcnt* us ili((C«i!iK' »* ihoK' ihnl nrc tn^h f Wh.i! rf|>lilM ori' u»mI n» f^' 
"it vafieij uf lirii ii nioit a|>I I" J 



USE OF SHELL-nSH AS IXIOD. 



2011 



jf shell-fish. All fish that have commenced to assume the pu-fl 
trefactive state are unsuitable for vjwe as food, aud should neverll 
tie eaten. We may also say that all fish lose by \tem^ kept, | 
ind it" it 18 desired to serve tnem in fuU perf'eetioii, they should 1 
Be ctxiked soon after dentb. j 

^^mong the substances that are highly prized by epicui-es is I 
^fcrepamtion of the roe of the steilet oi' sturgeon, which ia I 
Bown as caviare. The best is obtained from Russia; that" 
ierived fnim the Ameiican sturgeon is very indiijestible, and 
:>i'oduce3 severe gastric disturbance. At the heaci of the list 
>f edible fishes we place the ti-out and sahuon, which are uni- 
rersally esteemed, and yet it is stud that even these may be im- J 
>r«ve(l by castration. I 

Of ahell-fish the oyster is the most iligestible, especially when I 
;aten raw, and with the addition of a little Cayenne; they are I 
rt'ell adapted in this form to invalids who are just conimeuciuff 1 
x> convalesce. Those tliat are tiunsphmteil are edible at all ■ 
ieasons, and possess a good flavor dunng the spawning sea- 1 
wn, /. d, May, June, and July, ^\■llen the native oysters are not 
sdible, O^'sters are generally thought to possess an aphrodia- I 
iac power, but the statement is not ibimded on facts. | 

In Switzerland the snail is much esteemed, and gardens are I 
:levoted to their cultivation, Crabs and lobstei-s ai'e held la 1 
iiigli repute in .all cities on the sea-shore, and the clam audi 
iuus;;el also have their admirers, but the latter are more Hablel 
than any other food to jiroduce symptoms of poisoning. ' 

The effects of the various methods of cookmg have been 
shown in the tal)le (page 59), in which it is demonstrated that 
the method by broilmg is the best. In boiling, a considerable 
portiim of the nutritive material is removed by the solvent ac- 
tion of the water, so that we can prepare in this way extracts 1 
of greater or less strength, which are generally known as soups. I 
If the meat is placed in the water wlien it is cold, and the tem- 
perature of the liquid gradually elevated, the loss of nutritive I 
material will be fai' greater than wlien the flesh is drojiped into I 
boiling water. In I'oasting, the crust that forms on the (-xte- j 
nor of the joint prevents the escape of the nutritive portions ; 
and though the mass may lose more ^veight than if it ^vaa J 
boiled, owing to the evaporation of water and melting of tat, 1 
it possesses greater imtritive po^ver. It is said that beef loses! 

la iinio fiHli fit lor im- ? Wlini ia cntinre ? Wlini is Ihe cffuct of rnslmtion on llio ^t^WM 
otfi'Ut'iJ ITnJcrwhni furm in iIiq njnicr mixi iliirchtihlo ? How ninv it Im reiKlorcd cililil« I 
mail ncn^nna? Wlini uilicr i.lielMi»li iirc used va fM-i? WliatU iIid best mclbod of cook-. 1 
iag? How ihaulil suiips l>o pruiKircd 1 ■ 



WHEAT AND BYE FLOUIi. 



by boiling one fourth of its original weight, and mutton oqc 
fifth, whereas they both lose about one third by roasting. 



LECTURE XLn. 

VEGETABLE FOOr 



Vegetable fbod leas whoksome than Anhnol Food. — Bread heet a<lapf^^ 
ta J>yi^eptica. — IndigfsttMe Character of Pastry. — Jimted or Erijut li*/^- 
— rt^iidicea agaimt the L'se of Oatmeal. — Ise of Corrimrml — /'d^*'- 
gra. — Polenta. — Uee of Leffttmais. — IndigestibUity of Niilt. — Ffrrt *if 
Cooking on IHgeetibilUy of Potatoes. — Cse of rate and eooked Vid^K'ff^ 
— Salads. — Sugar doe» nvt injure Ute Teeth. — Concetttrated SolutionB *^ 
Sttgcir »H(>8( Digestible. — Classification of Condimmts, and Efftct of * **" 
ai'ficient St/pphf of Salt. — Avc/tovy and JHoater Pastes. — Use undAl'^'J* 
of Vinegar. — The aromatic Condiments. — Effect of Climate on the -^"^ 
tvre ofOiet.—^ect of OcctijxUion on l>ict.—Idio8yncra8iea.—£^'ect ^ 
Irregularity in the Evacuation ofJ^ccs. 

Fai! greatei' care is i-enuisite in the selection of vegeta.V' 
than of animal food, for there are many plants which jio?s=«:^' 
an injurious action on the human system, and many of th***^ 
which are in ordinary use frequently become so changed in tli^^' 
character ns to cause violent disturbance to the digestive t* J 
paratus, ivhicli is sometimes so severe as to result in detith. 

The chief article of food of a vegetable origin is brejid, «»• 
we have (in Lecture XI.) mentioned some of the varieties f*^ 
ployed and the mode of prejmi-ation, When bread made fr«-* * 
the finest wbeaten flour pi-oduces dyspepsia, it will be genei"^ 
ly found that the flour which contains a ])ortion of the br"**- 
will furnish bread that will be digested with ease, the br** 
acting as a geutlo stimulant to the stomach and iutestineR. 

Leavened oread is prepared by the aid of a ferment, as yeaS-'" 
unleavened bread is made without. By tlie pro|>er use of f'^'^ 
ments the disintegration of the starch granules of flmu-is ini*' 
ated ; it therefore follows tliat bread so prepared nmst be mc»* 
easily digested than that made by tbe use of baking powde?*'' 

Tlie preparations of wheateu flour known ns vermicfiH s-**; 
tnacarojii are very nutritious and easily assimilated ; but ■*■■' 
articles of pastry are unwholesome, and cause dyspepsia in<-»'' 
fi-equently than anv other substances^ The lighter varieties *^' 
puddings are wholesome, but those made with fsit or suei i**^ 



What isiherflliitiTelnssofwcigMof lieefniiii mmiou bj ronaiiiii 
eUbles ns tiniffiTTnlv uho1«Kimp n> nniinnl food? Wlint larielj of 
nie bjr djtpepticsf ' la ptulv; UigcBiible? 



i|{HU(lbuiliiigr An •^ 
■ ■ . ben adajtlcJ ' 



EICE, INDIAN CORN, AND LEGriTENS. 



20ffl 



very i ^ 

iiiKi, by covering the particles of flouv, protect tbem from tb^ 
action of the gastiie juice. fl 

lly« is also extensively used in the preparation of bread, ancH 
is an excellent article of diet. It is, however, liable to a diafl 
eas^e called the rust, wliich also passes under the designation of 
spurred i^e.or ergot; such grain, when used for any length of 
tiiue as an ordinary article of diet, causes dry mortification of 
the extremities. > 

/'Though it is highly nutritious, there is a common prejudioafl 
/against the use of oatmeal, many people thinking that it is apn 
(to produce cutaneous aft'ectious. jl 

Rice flour "HntTjiotatoeaareoften added to wheat flour in tliq 
preparation of bread ; there is no objection to their use, and infl 
skilmd lianda they are a decided improvement, Indian corn is' 
in common use in this coiuitiy, and in the Southern States has 
always been the chief article of diet for the slaves. It is not 
well adatited to the constitutions of those who are liable to in- 
testinal disturbances, and who aie not accustomed to it. Many 
will be sui-prised to leam that in Lorabardy a loathsome dia- 
ease. called ^>f//(?;/r(7, has appeared dnnng the liutt century, . 
which ha^ been ttttiibuted to the inti'odnction of Indian coi-qa 
as an article of diet, the Italians being very fond of a dish call* 
gl^ polenta, which is a cornmenl pudding. I 

■I The legumens, as peas and beans, are highly nutritious, andl 
Brni. when dried and thoroughly cooked, an excellent aiticlflS 
^if diet for those who are obliged to work baitl. Some varie-' 
ties are eaten with the pod when tliey are very young and ten- 
der, but they are very indigestible unless the)- are well boiled. 
The nuts that are introduced at many tables are all more or 
less unwholesome, since they contain oils which are not acted 
on in the stomach, and consequently the digestion of thefarina- 
lous parts is thrown on the loiver intestine, and is imperfectly . 
rformed. ■ 

i> Of the roots, the beet, carrot, parsnip, tuniip, etc., all contaiM 
Wgar, and are slightly nutiitive when youii^. They shoidd ba 
well cooked before they are eaten. The radish, onion, leek, and 
such articles are all indigestible, and should be employed in 
Diall quantities as condiments rather than as articles of food. ' 

Whj nre Rrticlus prvpnrei] wilh fnt or siicc indigestible? Under nlint rircuniEtnnres !■ 17a 
Btfor HM? Whnt pn-jiiiiica exisis ngiiinat this nue oronlmenl? Is there anr olijeciiurt in 
^addilioD of riee floiir or potnines 10 biend? Uiiiler whm rircutnaionoci d'oai coiiiinenl 
grtet What i< pellagra? Wlinl ispuleiim? What are legiiiuciis? Arc they ndiipud' J 
U coDiliiuiions? Why ara nui« iadigeitihle ? M 



LANE, umm^^^i^m smm!^ 



VEGETABLES ESIPLOTED A3 FOOD. 



Of the varieti&s of potato, those wliich are mealy are the 
most digestible, hut it depends to a great extent on the man- 
ner in which they are cooked. If they are sodden in salt wa- 
ter, tlie best potatoes «-iU be injured ; the pro]>er niethtnls to 
be employed in preparing them is either by steaming or roeist- 
in^' until tliey almost fall to pieces. The potato is nt time« 
liaiile to be destroyed by a disease which commences in the in- 
fririor, and wliieh is eonimonly known as " the rot." It has oo 
casioually pi-odueed great suffering among such nations a» the 
Irish, who make it the chief article of food. The sweet or Ca^ 
olina potato is very nutritious, but is not so easy of iligestion 
as the Lisli or common |>otato. 

The vegetables of which the cabbage, a-sparagus, spinach, 
and cauliflower are examples, often disagree \vith those who 
are not dyspeptics, and the great majority of peojile find that 
cabbage is much more digestible when eaten raw than when it 
h cooKcd. Lettuce, celery, and the like salad herbs ore al- 
most invariably employed in the uncooked state, and often 
agree with a dyspeptic when mingled with oil, mustard, vine- 
gar, and condiments, while in the undressed state they would 
cause a severe attack of indigestion, 

Mushrooms, cucumbers, and'tomatoes are all held in high es- 
teem as delicacies, yet they belong to families of which some of 
the membera are very ixjisonous. This is esjjecially the case 
with the mushroom and cucumber. 

The fniits are all wholesome in their proper season, when 
they are fully ripe, and have not been kept for too great a pe- 
riod of time. Some, as the varieties of melon, produce diar 
rho?a in certain people, and are often suspected as being the 
cause of visitations of cholera. The evil consequences which 
arise frttm the use of these and other fruits may be to a g^at 
extent avoided by carefully rejecting the skins, core, and seeds, 
ami using the pulp only. 

All fruits contain sugar, which is very commonly supposed 
to injure the teeth, but this is a mere prejudice, which has 
probably aiisen on account of economic reasons, for it has no 
true foundation in fact, since the negroes of the South in llie 
sugar season partake of the juice of the sugar-cane very freely. 

What varietiM of pomo are most diL'cstiblv f IIow <lo<4 rooltinE aBixt ilio digntihiliijr 
orpotstoeoF Whnt is potarnroi? la the Cnrolina iHiinio m difti^libk as ili« rummon piv 
tato? In n-liRt farm U cnbbngo tnntt titgcslilile ? ITmli^r what furm nre ihn ciOnd hdbi 
niosi ilipi-atihle? flow mnv iliu ovil consciiTH-nceti uf cniinu Trnit Im in n grtui mi-anui 
niiiiili^d? Wlif arc ivo Jiistinci] in iuppaaing I bat tlie (rna aso oC fugiir duct nui Injnm tte 
teeth? 



^^^^B SUGAR AND CONDIMENTS. 20i9 

Btd grow fat on it, yet their teeth are not injured, but ai'e uhm 
Brersally known and admired for tbeir beauty of fonu and! 
whiteness. It is estiniatei] tliat in Fiance the annual ccilriunip^ 
tion is 5 lbs. per cajiita ; in thf I'niti'd States, lu Ibi*. ; ami iiM 
England, 14 lbs. Concentrated s-oliitions of .sugar often digesM 
readily, when a dilute birup, in wliieh the amount of water jfl 
veiy great, is highly indigestible. It is owing to this eauBS 
that tea and coffee often disagree. fl 

y Condiments are substances employed to assist digestion S 
they generally contain either a bitter aromatic or an ouy acrlM 
principle. Another class, of which salt is an example, ai-e pui-M 
ly saline, and we may justly I'egard it as the most important ofiB 
all the condiments, since it is absolutely neceasary to the jirop-J 
er performance of digestion ; and \vhen it is not used in inoperl 
quantity both by men and aninnds, we find that there is a dis- 
position to the formation of parasites in the digestive canal; for 
m those countries in which the criminals are foreed to subsist 
on a diet from which salt is excluded, the unfortunates are lit-J 
erally destroyed by the worms that are produced in the digests 
ive canal. In ancient times, salt was the first thing jilaced on^ 
the table and the last removed; and it is still the custom 
among the Dutch families, when they change their residence, 
to take to their new abode first of all things a Bible, for God's 
blessing ; <■/■ f'Off of salt, as the emblem of hospitality ; a loaf of J 
bread, as the symbol of plenty ; and a broom, to ty])ify cleanliS 
ness. fl 

The anchov)-, bloater, and other paste-like condimentp, whicM 
re prepai'ed from salted fish, are very indigestible, and shonldj 
Uv" be enii)loyed in small quantity. ^ 

Vinegar alone, and in the fonn of pickles, is a useful condi- 
fUt, and we have already alluded to llie jirojierty it posses-ies 
f assisting the gastric juice. Tliere is a common idea tliat 
hen freely used it reduces inihon-jmiiit, and aids in i)roducine|J 
dender, spider-like waist. Whatever effect it may have o^ 
|A figure is of very small importance compared with the f'acM 
At, when used in such excess, it is utterly destructive of thM 

Bestive powers, and, by the indigestion produced, causes nolfl 
y the waist, but all the other tissues to shrivel up, and ren 
:efl the sufferer to mere skin and bone. The action of leinonSM 
I other acid fruits and juices, is similar to that of vinegar, fl 



\fn ilUnp'ca 7 



ililiitc fi<j!ii(ii>ns of Biicnr moi'e dij^vstibEc? Why do im nnd coffb^ 
nlini dn)vt>s (if (iilwtaTiccsdo cnnditDEDla belong? To nhnt clntiK dl 
1KB cult [H'lone? What ia llio effect of An inadcqnnlo aupjilr □r»nli? .' 
■uch pDElcs digcniblc ? What is tbc i-Scrt of i!io abnso of Tinegur ? 



206 



EFFECT OF CLDIATE AND OCCUPATION ON DIET. 



The aroDiatic condiments or spicea, as ginger, cloves, nutmeg, 
cinnamon, pepper, mustard, horseradish, onions, etc., are exten- 
aivelv eninloyed in all parts of the globe, sint-e tliey assist thf 
deficient aigestive powers of those whose stomudisare t 
and aid in the digestion of aiticles of food wliioh would 
wise cause indigestion. They act 1)V stimulating the 
of the mouth and stomach, and caiismg them to secrel 
fluids with greater rapidity. 

Variation in climate should be met by variation 
ture of the food. An Englishman may drink with i; 
beer and alcoholic fluids in ins native land, but if lie ti 
the habit under the hot sun of India his liver is 
eased, and his life shortened or forfeited. The inhabi 
hot climates require but little resjiiratoiy food ; they 
quently freely supplied by Natui'e ^vitIl a great' vi 
sweet fruits, the sugar of which furnishes all the coti 
material they need, but in cold climates a large qa 
calorifacient food is required to sustain the animal 
ture. The inhabitants of such regions therefore rew 
use of fats and oils, ivithout which they could not exi 

Occupation also exercises a great ini^uence on digest] 
soldier mil consume his allowance of fat jxirk and oean 
day while he lives in the open air and has to undei 
drill. A laborer will also enjoy the same food wi) 
but if a student or pereon of sedentary habit* pai 
many times in succession, he will sutt'er severely fi-om 
tion so long as he continues his inactive life; but 
leaves his desk, and, taking his rod or rifle, lives in 
air, he will enjoy a daily allowance of givss oleagini 
with as much relish as a soldier. 

After paying proper attention to the influence of the 
of cooking and the occujiation of the indindual on tjiejlj 
ibility of food, there t^til! remain certain personal , 
or idiosyncrasies, as tliey are called, which e-neh pel 
notice and study for bimseU" Some will suffer tori 
eruptions on the skin if they eat ever so small a jnirtlon 
shell-fish. The odor of a rose or of new hay will pmduce nsl 
ma in another, while they affonl pleasure to the niiijoril 
people. When, therefore, an individual finds that any article 
of diet pi-oduces trouble in his <ligestive svstem, he must exert 
his o\vn good sense in the matter and avoid it. 

How i]o tbe nromalic contlimenrs mc? Vac* 
ceilinf! fooil ? Whnt is Ibo eficct uf occupition i 
by idiosyncnuicB? 



< 



EFFECTS OF HABIT. 207 

Not only ahoiild regiilarity be observed in taking tbe meals, 
but the evacuation of the fieces Jrom the intestiiies tshould take 
place every day at the same hour. By atteiidinjf to this dutv 
ritb l-eaularity, a person ■\vil] enjoy fai- l)etter health, and avniJl 
pose disat^reeable and annoying headaches which are certain 
arise wlien coD.stiiJatiou exist?. Medicines may be used to 
ffoni relief for a time, but it is the tendency of most purgative 
flrugs to produce a constipating effect after the purgative ac- 
WHi; they Bhould be therefore avoided, and the habit ofevnc- 
llting the intestine at a certain hour established, when trouble 
"rill very rarely arise. 
Habit, is tlif; most powerful of all agents in its effect, not only 
I'jDn the digtstive, but also on the other systems of the body. It 
Jilionld tlinit'ore be cultivated to as gi-eat an extent as possible, 
,: the Iiody quickly accommodates itself to any given duty, 
nd accoraplishea a definite amount of work with far greater 
B when it L9 accustomed to it. 



LECTURE XLUI. 

FLUIDS USED AS DRINK. 

■ t/int jiro'liirr. Thirst. — Temperature at lehic/i Water thou^ be etn- 

t.j^oytil an I h- ill h:^ Use of Ice. — Natural Waters, — J){0'ermcfs between 

VMatn nnii ^^i>riii<iM''Jta: — IW'^cta of Livie-ieat^n- on (hv St/gtem. — Jiffect 

mifflalinra on rnjMifi/ of Absorption of Water. — GoUre. — Materials 

"ytiohte.for makinn Waterpipea and Tanks. — Protection of Lead J^'peg, 

''PneautioiiM to be. emjdoi/ed in the Use of Lead Pipen. — Piirijiealion 

fWater bif Filtration and Distillation.— Ofijeel ions to the Use ofmcect 

int». — Toasl-^ealrr. — Gruel. — Properties of Tea and Coffee. — Intro- 

fr^uUfcu of Tea. — Classpieation and Composition of Tea. — jRffccts of the 

AhvM of Tea. — IntrodiKtioft of Coffee, — I^-eparation for Lse, — Ckoco- 

—Soda-walei: 

As hunger is the evidence of the demand of the system lor 
slid aliment, so thirst shows tin' desire of the body for fluid 
jrherewith to tlilute its oircuhitiiig juice, and ftinuNh the liquid 
pi]uirod for the urine and iteiNpiratinn. The experiments of 
^'uptiytren demonstrate that the i^eiisjitioji of thii'st may be al- 
ftived bv injecting water into the blood-vessels; it would there- 
fore seem to be dependent on the amount of water contained in 
he circulating juice. 
Water is f lie natural drink of men and animals, and the ma- 

E effect of rcjjularitT in evacuuling llie ftects? U|" n «h.it roDditinii iif iliii 



I 

I 



308 VAHIETIES OF WATER. ^^| 

jority of nations use St at tlie temperature it possesses when 
issuiu^ from the eailh. Some valetudiiiannns insist that it 
shmilil always be taken at a temperature of !'0° or llK^^ liut 
it appeal's far more natmal to employ it at lower degrees, such 
as 4i(' to 00", which is the oniinary temperatui'e of sjning or 
well water. The use of ice-water is objecteil to by maiiy; nut 
when we reflect that its temperature can nctt 1 le lo\ver than 32", 
and that of natuml water in fi-om 4t>° to fJU ', the objection ap- 
pe-ars to lie tnvlal, and not worthy of consideration. 

Rain is the pui-est form of water ftirnished by Nature. The 
first portions which fall in any storm wash the air, and remove 
the floating dust and noxious gases which it contains; this is 
admirably adapted to the wants of plants, but not 8(» well suit- 
ed to animals, though it is purer than the water usually em- 
ployed. The rain which falls dunng the latter part of a long- 
continued storm is absolutely pure, and may lie usetl for the 
same purjioses as distilled water. 

Sjiring and well ^vater always contain a certain jiroiKirtion 
of solid inorganic materials, dei-ived fi-om the strata tluvugh 
which the fluid has peiTolated. In lime districts the quantity 
of carbonate of lime in the water is very lai^e. and pnKluees 
diarrhoja when used by persons unaccustomed to it. The eril 
itwults of the use of such waters may lie in part avoided by 
boiling them, whicli expels the carbonic acid gaa in the liquid, 
and causes the carbonate of lime to be precipitated. 

It often happens, especially in lai-ge cities, that in passing 
thi'ough the soil the water dissolves enormous quantities of or 
ganic matter from some sewer or other receptacle of filth. Such 
water is often remarkably pellucid and pure iu appearance, but 
in its action on the system it is most deadly, proilucing the 
worst forma of dysentery and low fevere. The impuritiea may 
be detected by an oi-dinary chemical analy&ia 

Water, of all liquids, allays thirst with the greate-st rapidity, 
and is absor})ed with the greatest ease by the veius of the 
stomach. Tlie presence of a very small proportion of saline 
material in water reduces the rate of absorpti(m, an individual 
beint^ able to drink a far larger amount of niin or distilled wa- 
ter than of that obtained from a spring oi' uell. M'he n dJfr 

At wliiit Ivrnpcvnlilre is water gcnorelly cmplajcd ? Is ihi^re nriv nhjfi^tion to ihe TDnlrf^ 
mo iiso of ico J Wlini \* llw puroit fonn of nainml wat^-r? Are ihc lini nonioni of nto 
ihnt fall as well initcil tn tlio ffanU of animnla m ofiilanlii? Wtiitt ii the (lilr«r«ni«.b*|«|M 
■pring or well water nnd rain-n-nior? What is ttic rffcet nf liTne-iraier uti the mwn? 
How mny llio lime be remoTcd P What nra ilie injonliariiic* nf wnter conlnlnini; brpnlt 
Howdoi'ii (h<3 presence' of saline mulicr in »ater Jnllucncelu rale of ohwqiikM tj 






IS of the Blomacli ? 



pATEKtAXS USED IN THE CONSTRUCTION OF WATER- VESSELS. 209 

tillod water lias heen taken in these large quantities, it passes 
off almost immediately by the kidneys, the urine gradually 
containing less and less s<ihd mateiial. It has been humorc)US- 
ly pi-oposed that in diseases we should, by drinking enormous 
([uactities of distilled water, wash out the system just as we 
eleanse a soiled garment. 

It was formerly supjwsed that the neater obtained from melt 
ed ice or snow produced the disease known as goitre, ^vhich is 
a swelling of the glands of the throat; but as it exists also at 
the liase of mountains on which snow never falls, it is evident 
that it is due to some other cause. The elephantiasis, which 
pi-evails in Egypt, was also supjiosed to be piXHluced by the 
use of the watere of the Nile ; hut it is almost impossible to fix 
on water as the true cause of these and other diseases which 
are endemic in their nature, since they may also he pmduced 
by peculiarities in the air or vegetable growths of such regions. 

When the water fi'om lakes and livers Is placed on ships, it 
undei'g<jes fermentation in the tanks, and deposits a large 
amount of sediment. After this punlication, though it may re- 
tain the odor and flavor of some of the products of the action, 
it is much more Avholesome and less liable to produce dian-hwa 
and other intestinal ti-oubles. 

The best materials that can he employed in the manufacture 
of the tubes for conveying and tanks for holding water are 
glass, wood, and ii-on, since they do not impart any poisonous 
qualities to it. Lead and copper are Uffedibut there are gieat 
objections to them, since if water is allowed to remain in ves- 
sels made of these metals it soon acts on them, and becomes 
more or less impregnated with metallic salts, which render it 
highly deleteiious. In tlie case of lead, which is so generally 
used in cities, the purer the water, the more liable is it to act 
on the metal ; but when it contains sulphates iu solution, the 
Milphiiric acid. having a great affinity for the lead, unites \vith 
its oxide, and tonus on the interior of the pipe a thin insoluble 
coating of sulphate of lead, whieh protects the pipe from far- 
tlier action; wnsequently, the water drawn from old iiijies is 
usually free from lead, while that taken from a pipe that has 
just been laid is generally more or less contaminated. Even iu 
^^le case of old pipes it is best to reject the fii-st jjortions of wa- 

^^^nVhnl u iioiire, and whnt wna nupposGd (□ be its criiso ? Wlini change nrears in ilio riTci^ 
^^^Ber |ilaeed in the tnnka of »hi]>i>? Whnt nro iho benl motcrinU tlinL can !« cni|ilnjcd in 
^^^Knano failure ofwatcr-pipesiindlnnkfi? VVhnC r.iricty urivnirr nc»>vithlhcETcnic«t rn. 
^^Hkiun Ipad pipes? How do u-nwrs ronmininf! f^ulinc mnilcr protect Iho lend Tiom rarru- 
^^^Btt What precnutlonsBbouId be taken in utiiig irnicr front lend tiiiics? 

I 



PfKIFICATlON' OF WATEK. 



ter that are dni^vn in the morning, and whicli have n'st<^l 'v^ I 
tlif pipes dming the night, since they fi-equeiitly contain no ftp ■ 
preciable amount of lead, even thongh the pipe is coated m tb« I 
interior with a layer of sulphate. I 

Many of the impurities CDUtained in water may be separat*^ I 
by filtration. On the gi-eat scale, this may be done by jiassi«»^ 
it throngh many alternate layers of chai'coal and sand, whifDJ 
shouhl be from time to time renewed. In Paris tbei* is x^^ 
establishment at the Qnai des CeUhtinH, where an immeti^^*^ 
amount of water is purified by first passing it through fiixingt^^ 
then through filters such as those descril>ed above, and linal I j 
causing it to fall through air in a fine rain, to allow it to absow^ 
the gases it has lost during the purification. I 

On steamers, a liberal supply of water can be olitiiinod V^^^J 
the condensation of steam. '1 he only objection to distilled n — ^* 
ter is its insipid taste; but this can easily be avoidetJ by aeaC^ 
tating it with air, or allowing it to fall turough a column i—^-^ 
air, as in the Paiosian establishment spoken of in the precedir^» 4 
paragraph. 

The mfusions of various animal and vegetable substanc^t;^ 
are extensively employed by all nations as drinks; some xi^^^ 
these, as lemonade, are acid, while others are sweet, as the «^^ ' 
sun-ee, and the various simps prepared with fruits and sugiw— "* 
Though such fluids are often gratifying to the ])alate, they ai ^ 
as a rule, injurious, and produce intligestion, attended by heai 
burn autl ilatulence. 

Toast-^vater, made by immei-sing well-toasted bread in i 
water, is to many a verj- gi-ateful drink, and rarely does hai 
It often relieves the breath of the disagreeable odor that it pt"^ ^ 
Besses in some pt^ople. 

Gruel matle tram coarse oatmeal is an excellent article eithi 
for breakfast or supper when the powers of the stomach haw^^^ 
been enfeebled by indulgence. It is also extensively employee^"* 
in the diet of parturient women, being very nutritious ao"- 1 
tending to relieve the constipation which usually attends tt.-^1 
period of gestation. J 

Tea ana coftee form prominent constituents in the diuly di^^4 
of the majority of the inhabitants of the globe. They are pt^**] 
sessed of considerable power as nei-vous stimulants, and a**^ 
pleasant leverages. It has been satisfactorily demonstrate?;*' I 

ilijw roiiy imiiuritiea lio remiiTcJ from wmcr? How mny ihe insipiil tantit iif (li>tlllnl !•"*■ I 

ler bj reinovwIF What nrc ilio Dhjertioos to Iho use of swrct drinks? WIibi i< ttaa-Br*- I 

icr, and nhnl nrc its propcrticg? Vnict ithnt condiiion!) of ilic t^yetcm tloa miUiHal fn*'' I 

nSurd relief? What axe il^cgcucrut properties of lek ■mlcoffoc?' I 



TEA, COFFEE, AND CHOCOLATK 



■ they not only act as direct stimulants when taken after 
nwrfurmance of fatiguing work, but also prevent the waste 
Ksues during labor, and ai'e therefore of value from an eco- 
Kc point of view. 

Kea wa-s first imported into Europe by the Dutch in 1064. 
Bis now extensively employed as a drink by many nations 
Bie form of an infusion of the leaf. There are many varie- 
■' of tea, but they may all be reduced to two orders, viz.. 
B and blaek. The A-arietiea of the first clasa in common 
Bare the fajson^, imperial, and gunpowder; of the second, 
W souchonff, ooIoTiff, pekoe, povchong, bohea, carnpo, etc. Au 
alysia of tea shows that it is composed of extractive, resin, 
auin, gallic acid, and mucilage, the greatest proportion of the 
tringent principles being found in the green teas. When 
ken in too strong an infiision it produces restlessness and 
ikefulness, owing to its stimulating properties. 
Coffee was first publicly sold in England in 1652. The best 
that from Mocha, on the Ked Sea ; next in value is the Java ; 
tiile those from Brazil ai'e the poorest. The value of cofi'ee 
pends in a gi-eat measure on the care ivith which it is roast- 
; if the heat has been deficient in intensity, or has not been 
ntinued long enough, it is bitter ; if it is applied for too long 
>eriod, all the aroma is expelletl, and it is tasteless. It is best 
nd and use it as soon as it is roasted, and when ground 
ly be kept in closely-stopped bottles for a considerable 
1 without deteriomting. It is better to prepare it as an 
fiision than as a decoction, for in the latter method the long- 
ntinued apijliciition of heat expels the aromatic principle. 
Coffi'e is both tonic and exhilarant, and is held in high cs- 
em by the student; it is regarded as an intellectual stimu- 
at, and has been the brain-fuel of many distinguished authors 
id litterateurs. When fi-eshly made, and taken in small quan- 
tafter a meal, it assists digestion ; but it should not be used 
fccess . or ming led ^yi th sugar or milk, as it is then aptjg 
|wnce indigestioa. 

ciiocolate is the pulp of the cacao or chocolate nut, which ii^ 
asted, ground to a powder, and flavored with vanilla, cinna- 
on, or other aroraatics. When prepared as a drink it is very 

rVhen nnd Uy whoni wiu tow intraducEii inio Enro|M;7 Wlim aru ihu iwo dnswi of 
mt are [ho I'imnliMii'ntH of ten ? Whicli cln^g oT len contains tlie Ini^mt praponiu' 
ringeoi|iriiini.l(!»7 Whni imho effect of ilio iisoof nii cxwisof Wa? Wlien wna eoffw 
^ncetl ? WJmt i« tlio flnigit rnrici}' of colTin 7 How U iho berry proparcd for dro, anil 
scanlioiii slioiitJ lie tnkcn in iL» |iTiT|inrntinn f How may ils Aromn bo retained 1 
t tho pro|iertie8 of coffee ? Eow iboul J it be iisc<l afur a mi'nl ? WImt is choi- 



■212 niE ALconoLic Ligroiia 

indigestible, and sltoiilrl be avoided by all who have a touden. 
cy to dyspepsia. 

The soda-%vater made by condensing and diasolviiig I'aibonir 
acid gas in water is a pleasant and agreeable drinK, ami iicB 
OH a gentle stimnlant to the gastric mucous membrane, Wlivn 
the powers of the stomach are reduced by the excessive use of 
stimulants, or when there is prostration from over-excitemenli 
a little brandy mingled with the soda-water descrihetl above Ji 
DUe i>f the best restoratives that can be employed, the carlcmic 
acid of the soda-water seeming to hasten the absorption nf llie 
alcohol, as is shown by the rapidity with which the brisk wine^ 
as Champagne, produce an intoxicating efteet. 



LECTURE XLTV. 

ALCOHOLIC smiULAJfTS AND TOBACCO. 

Classification of fermented Liquors. — Times at icAiVA alcoholic JTHfA 
thoiddbe taken. — Effects of the Abuse of akufioUc Drinks. — flmj""* 
liotts of Wines. — Mvst. — Imj^rfection of our Orapes. — Componlioit <tf_ 
Wine.— Its Bouiptet.—B^tet of Age.~Gause* that L.fhttnce its iatOP- 
cuting Power. — Port. — SacJia. — Saeet Wines. — Malt Liquors. — Liqvc"*- 
— Liquors: Brandif,Whlskt/t6in, Rum. 

Thbaeeo, its Introductioji. — Forms in v>hich it is used. — Effeelt on the *■ 
factory Nerve. — Principles in Tobacco, — Effects ofeaxeaaiot Sntokinif- 
Training. 

Is the class of fermented liquors we include all varieties 
wine, ale, and other malt liipiors. and the stR>ng spirits, 
brandy, whisky, etc. 

Alcoholic fluids are of two classes — those which contain 
small percentage, of alcohol, such as beer, ale, and the Ug"_- 
wines, and those which contain a gi-eat pei-centfuje, as bran(> 
and whisky. The fii-st are employed to such an enormous e "^ 
tent by certain nations as to have become national in the ^ 
character, the English and Germans resorting to the use of tl*^ 
different varieties of beer, the Fi-ench and South Euroiwat^ 
employing claret and light wines, and the North Eun>peai^ 
the sti-ongest alcoholic litjuors. 

Alcohfdic fluids, when used in mwJeration, belong to th 
class of respiratory food. If taken before exercise or laW 

Ii it digpslible? What is Eoiln-ivatrr ? Ilnw iliwa il art itIimi minirli^il wiili •liaiuUn'» 
GiTO cxntnplei of fermcmed liniiiii^ Wlint tin the tivo fl»»ci ofBlcnhnliv liqnonf W1i<»' 
naiiuiM employ ilic Dm clnu of liquors? Whni nniinnt nic linlutiiatLil lo iha wa <^lb^ 
■trong liqnnrvf To what clius of food do ihc nicoholiu fluiiLi bclung? 



COMPOSITION OK WINES. 



:hev may be injurious, since they stimulate the individual to I 
intlertake a greater amount of exertion than his system can 1 
^eai'. The proper time to take stimulants without injury is 1 
ifter the labor or work is finished, when they aid in restoring 1 
;he system to its perfect state. | 

The excessive use, or rather abuse of aleoholie fluids, is, of i 
wurse, not to be for a moment tolerated. It not only for the ] 
ime converts the man into a beast, but steadily undermines I 
;he constitution, utterly destroying the tissue of the kidneys i 
uid other organs, and producing such changes in the substance I 
>f the brain as to cause incapacity and mania. I 

Wines are prepared from the juice of the grape, which ia I 
called mn^f. This is caused to ferment at a certain tempera- I 
;ure, by which alcoht)! and carbonic acid are produced, the pro- I 
portion of alcohol obtained depending on the amount of sugar I 
n the must. In the juice of our domestic grapes the sugar is 1 
leficient in quantity, and it is necessary to add a sufficient; I 
imount to exhaust the ferment in order to make a good w*ine. 

When analyzed, wines furnish the same constituents; in ad- 
lition to alcohol, there is water, mucilage, tannin, coloring mat> ] 
;er, various salts, and acetic acid. The flavor of the wme is 1 
called the l>oiiquet, and is probalily due to an oily compound, 
which in some varieties exists in the fruits, and iu others is the 
:)ruduct of the vinous fermentation. Many wines, as sheriy, 
ire flavored by the addition of almonds. The stimulating 
,>ropertie8 depend iu a great measure on the amount of alcohtu 
:ontained, aa is shown liy the following table from Brande; 



Murrain 351 



I'm . 

Miidoira 24 

" avernffo. 22-2 

Sherrf, srernge 10-2 

I.nchrytna Cbriili 107 

Vlc\»g% 180 

Cnpe MoBWl IS-2 

Cape UadeirB, nrcr- 



BB*.-- 



CalcaTclln .. t»-l 

JKhiim Hermiuuec I7'5 

wta. 



lor. 



Suiircmc \i 4 

BurKumJf 14-A 

Hock, KTcrHge S'D 

Itudcshciini^r.iiverafra t:-.'i 

Joliannubereer B-7 

BnrBAC.. ■" " 

Chnn 



■ngno... 



Kcd HcnniiBge... 

Fronlignnc 

Goo<id)erryWiiic. 
Orsiific Wine 



. 12-5 
13-3 



Tntay... 

El-lcr Wine... 

Khenibh 

Cider 

I'enr 

Mud 

Ale... 



...6 to t) 



Brown Stout 7 

Smnll Beer IB 

Brandj 63 

Ram 68 

Scorch Whiskv 54 

Irish Whisky .'. G4 ' 



,ge impresses great changes on wines, which render theni I 

At wbnt time should siimtilBiiti bo tnhcn ivhcn Ihev nre nceUcil lir the ETEtemF What if J 
llic effecl of the nbiise of alcohnlic mimnlnnls? How arc *\wi [■re)mrell? Whnt U iha J 
nuini) giTEn to the unfcrmonied f^pn-jiiiec? What i;oTerns ihu amount of alcohol in iha I 
nine? WliRt Bdilition \f iicccssiiiy in ihe cnse ofrhe pipes of the United States? Wbat 1 
ire the contiitiients of wine? Whnt is (he bouqmiT Upon nUat ingrediciiC do the ni 
laiing pTDpertitiDf tho wine depend? 



214 SACKS, SWEET WINES, AND LIQtrECRS. ^J 

more valualtle, anrl less liable to produce hepatic and i-enii 
troubles. The tartar, and a part of the coloring matter, are di 
posited in the fonn of a crust, and the alwiliol either is unit* 
■vvith, or is converted into the oily matenal, so that the bmiqw 
is improved. 

Burgundy wines are far more heady than clarets, though thi 
proportion of alcohol is generally less; this is apparently tlui 
to the peculiar character of their bouquet, which is very po^^cj 
fuL Of all the Asnnes, claret is Ijcst adapted for ordinary ilaih 
use, since it contains but little alcohol, and its astringent bitte 
principles often aid a feeble digestive appai'atus. 

Port is chiefly used in Great Britain, am! is especially pi 
pared by the addition of a large amount of brandy, to increj 
the streng;th; tannin is also added, to give the desired astriu 
gency, rendering it almost impossible to find a piu-e article in 
any part of the world, since these impurities are added at tht 
vineyards to adapt it to the English market. 

The sacks, or dry mnes, in which all the sugar is converted 
into alcohol, and of which sherry is the most common example^ 
are in very tjeneral use, and are much less apt to cause gouts 
than port. Many persons who can not drink slieny without 
an attack of indigestion can use Sladeira with inipunitj'. 

The sweet whies, aa Tokay and Malmsey, diner from the 
sacks in that they contain a large (juantity of sugar that has 
not undergone fermentation. They are not \vell adapted to the 
stomachs of dyspeptics, and should only be used as cordials. 

Cider, perry, ale, and other mild liquors, are very extensively 
employed, being in some countries national in their character; 
and although the ultra fa.stidious may regard the malt liquors 
as vulvar, tney are nevertheless one of the best fonus in which 
a mild tonic and stimulant action can be obttuned in feeble 
constitutions when they do not disagi'ce, which is often apt to 
Ije the case, the larm^ amotmt of extractive they contain render 
ing them very liable to take on an acetous fcnnentatioD. 

Liqueurs are made-bj' adding sirup to an alcoholic solution 
of various aromatics, as aniseed. They should only be used in 
very small quantity. They sometimes contain naivotics, whidi, 
adiled to the alcohol, renders them much ninre noxious. 

The strong liquors, as brandy and whisky, are obtained by 

WliBt change does ngc Impress npon wine ? Dnca the itimntiling proncrty oliriit 
■Ir-wnJ on llie proportion of nlcoliol ? How is j-rl prepared for llic F.nxliiJi maitel! 
Wlint kre wckii ? Give rsnmplcs uf tlie twcrl "irics I'potl trhnc mnMitnen) Oo ihl 
mult lli]Bors Uepcnd for ihcir toaic propcrtiL-a ? What nrc liqucun, and bow mto ibq' ((*■ 



^^^^^ THE USE OF TOBACCO. '21&I 

Hrtiillin^ wines or the products of fennentation of grain, audi 
Hmdeuaing the slcobolic portions. Brandy is pi-epwed by thu 
aistillatiou of wines. Wliieky, according as it is made fronwl 
rye, or corn, or other grain, receives an appropriate designation^ 
That made fi'oni the potato is known ».%poteen. Gin is an al-' 
eoholic liquid, to which juniper bemes have been added, though 
the coinraon article often contains turpentine. Rum is obtain- 
ed by feimenting sugar or molasses. All these strong liquors 
contain between 40 and .00 per cent, of alcohol, as is sliown in J 
the table, page 3 13, and furnish respiratory food in its most coe'J 
densed form. They should always be diluted, and used iaj 
~ '1 quantity. m 

TOBACCO. ■ 

iThis weed is said to have been first sent to Europe in 1539J 
was intmduced into England by Sir Walter Raleigh. Itl 
at first much opposed by all the rulers and potentates of* 
Europe, yet, in spite of the philippics of James I., and the ex- 
communications of Urban VIII., its fascinations have enabled 
it to gain so strong a foothold that it can not now be expelled. 
On its first introduetlou into Constantinople, where it is now in J 
univei-sal use, any lover of the weed who was detected in thel 
act of using it was conducted through the streets seated on an^ 

Pj, with his face turned to the tail of his steed, and his cose 
ttisfixed with a tobacco pipe. 
Tlie use of snuff is perhaps the least injuiious of all thel 
methods of employing tobacco, but when indulged in to excessl 
it is the most disgusting, and liable to produce dyspepsia. It ( 
sooner or later deadens the sensitiveness of the olfactory nerve \ 
to such ail extent that the sense of smell is lost, and the Schnei- 
derian membrane becomes thickened, giving the voice a nasal 
twang tliat is veiy disagi'eeable to a refined ear. In some 
parts of the United States the women use snufl' to irritate their 
gums; this oflensive practice passes under the designation of ^ 
dipping. 

Momoh'ng is the most universal of all the methods of emj)loy- ' 
J tobacco. When first indulged in it is apt to produce nau-l 
i and vomiting. The active jinnciples are nicotiii and a vnl-^ 
atik oil. TJie first is the most volatile, and theretbre i-ises in 
the .smoke an<l enters the air-passages, where it is absorbed by 

Iton' sro the Mrong liijuun prcpnrcd? How arc brnndy. whisky, Rin, nnd rurn mnctuF 

IUI was lobaiN'o inlroduccil into Europe? What is Ihe least injririnos forai in i 
be iwed? Whm is in> iiliitnnio effect on t.lic olfiipiury nrne? Wtiin is mcum liy dip- J 
;7 WluU priDciplca of tobacco nre volatiliacd in amaking ? 



216 EFFECTS OF THE USE OF TOBACCO. 

the blood. When a jwrson smokes to excess there is no longer 
a mere sedative actiou, but the nen'ous system is powerfully 
affected, the hands tremble, and the action of the heart is 'mtt-T- 
fired witli, palpitation being induced. It is also stated that 
the long-continued use of tobacco in any form, and esjiecially 
smoking, gradually blunts the virile powers, and finally rendew 
men impotent. 

Chewimj i« one of the most offensive methods of employing 
tobacco, and is very apt to produce dyspepsia. 

Thainino, by which the athlete endeavom to put his body in 
the best condition for resisting fatigue, renders certain rules 
compulsorj'. They are ; to retire cai-ly ; to rise early ; to exer- 
cise freely in the open air, but not to produce fatigue ; to eat 
moderately of nutritious food ; to drink water, or a small alhnv- 
ance of some malt liquor; and keep the mind gentlj^ occupied, 
so as to'be free fmm ennui; and if the person 13 an inhabitant 
of the city, he should remove to the country. 

In walking 1000 miles in 1000 hours, "Captain Barclay lived 
as fiiUows. He bi'eakfn.sted, after returning from his walk,at 
five in the moming. He ate a roasted fowl, and dmnk a jnnt 
of strong ale, and then took two cups of tea, ivith bread ant! 
buttei-. llisi lunch was at twelve, and it eon8i.sted, on aIte^ 
nate daye, of beefsteaks and mutton-chops, of which he ate a 
considerable quantity. He dined at six, either on roast beef or 
mutton-chops, his drink being porter and two or three gla.'wes 
of wine ; and he sujjped at eleven on cold fowl. He ate such 
vegetables as were in season, and the quantity of animal food 
he consumed daily was from five to six pounds." 



ir pfti^ci on ihe P 



fKt of loiig-GonliDuciI c 



CHANGES IMPRESSED ON THE AlB BY ANIMALS. 



LECTURE XLV. 

HYQIENB OP THE ItESPIUATOliY SYSTEM. 

\anffea impreaaed on the Air by Animala. — The Aelion of Plnnts. — 7'he 
Black HoU at CidmOta.—The BUick AsMze at Ox/vrd—JWifitu of Car- 
' 'o Acid on Ote System. — InluiUiHanofCarliureUedlfyarogin. — FXre- 
^..ip. — Choke-damp. — £!ff'ecte of Salphurelt^I Hydrogen. — The Action 
f Cldorine on noxioiia X'apora. — J^incfplea of Ventilation. — Methods 
fWariniiiy by open J^res, by Stoves, and by Furnaces, with the Ad- 
^aniages and JHsadsanlaycs of each. — Objeetioua to the Use of Steam- 
f^eoHa in Rooms. — Advantages of the Steam-heating Furnace. 

Animals are continunlly renderinsr the air impure Ity tlie 
exhalation of carbonic aciil, and the "■liole mass wouhl be grad- 
ually vitiated were it not for the action of plants, which undo 
the work of animals, decomposing the carbonic acid they have 
expired, setting its osj'gen tree, and restoring the purity of the 
atmosphere. 

The history of the Black Hole at Calcutta ftiraiKhes an il- 
lustration of the poisonous character of the emanations from 
tlie human body. It was about eighteen feet square, and con- 
tained une hundred and forty-six pci-sons ; there was only one 
small M'inilow, ^vliich was grated, and the atmosphei-e was very 
sidtry. In less than an hour several of the prisoners were de- 
tiiious and raved for water, which, when given to them by the 
sentinels, failed to allay their thirst. In four houi"8 many had 
died, either by delirium or direct suffocation ; in another hour, 
ail except those at the -window were either dead or in a violent 
delirium; and at the close of eleven hours only twenty-three 
were alive, and these passed through a putrid fever before they 
finally recovered. 

In the Black Assize at Oxford in 1577, a prisoner was 
brought to the bar after having been confined in a small dun- 
geon tor some time. He was placed between the court and an 
ojien ^vindow, so that the wind carried the emanations fiom 
liis body toward tlie judges and jury, and many of them and 
of the spectators were attacked ivith putrid fever and died. 

The itfipurity ivhich is generally found in vitiated air is car- 

Wlinl. chnneo ilo nniniiils iminpsa rm nir? Ilow fn lis jiHrilv rc»rored? Wliiil ivns tho 
hialory (tf llie Black JIoIb m Ciilciiiiu? Wlint H-ns the liisiorv If the Block AseUc ni 0%- 
furd? 



218 FIUE-DAMP AND CHOKE-DAMP. 

boiiic acid , the effecta of the inhalation of this gas ai-e pain in 
tlie head anJ singing or buzziiig in the ears, losa of vtihintary 
powiM', and a strong tendency to sleep, disturbed respiratioD, 
and palpitation of tiie heart. 

Carburetted Iiydvt'gen is also very noxious. It is extensive 
ly employed as the llhiuiinating gas of our houses and street'i, 
and is fonud in coal mines, being known to the miners as/iV- 
diiinp. When mingled vnXh. air or oxygen it fonus a niixtan:, 
whieli, ou the approach of a flame, explodes with such violence 
as to destroy the mining apparatus, and cause the de^ith of 
many workmen. The products of the explosion are vajior of 
^vater and carbonic acid, which is known to the miners h* 
clioke-fhynp ; it therefore is unsafe to enter a mine aft«r an ex- 
plosion until the choke-damp has been removed. 

The gas that accumulates in privies, and such receptacles of 
filth, is sulphuretted hydrogen: when i-espired in the pure state 
it produces almost instant death, and when highly diluted it t* 
a powerfiil sedative. The antidote is chlorine; it acts clieni- 
ically, decomposing the sulphuretted hydrogen with great i* 
pidity. 

The emanations from the bone-boiling and other establish- 
ments where decomjwsing animal reftise act-uinulates are com- 
posed, to a certain extent, of sulphuretted liydrogeu audoffen- 
sive vapors, all of which may be destroyed by the action of 
chlorine and other disinfectants. 

The act of respiration is practically beyond the influence of 
the will. We can not, for any length of time, increase or di- 
minish the rate of respiration ; but we can eontml the nature 
of the air introduced mto the Inngs, and substitute for a viti- 
ated gas, redolent with disease, the pure, uudefiled atmo(ij>heric 
air, by resortin*; to a proper system of ventilation. 

Ventilation is not generally understood, yet the priuciple on 
which it is founded is perfectly simple, and readily appne<l to 
any apartment. It depends upon the fact that if a jnven 
amount of air is subjected to an elevation of temperature, it in- 
creases in volume, becomes lighter, and rises above the cool 
surrounding air, which flows in to take its place. We mar 
readily satisfy ourselves that warm or hot air rises by ascenn- 
ing to the upper part of a room in which a number of people 



What arc Oic ofTecis of (he inholniinn of carbonic acitt pis? What is the cfTect of ihe ■*- 
liolaauii of corbuiTlleil livilrogcn ? Wlint is tho difl'crcnre belwceii fire-dsmp and (lidM- 
(biDgi? Wlint is the gnu IhM aocumulnlca in jirivicf? tlnw DiBj it bo desDDjed? UpM 
vlini principle dto tlie molhodi of ventilation fonndei] ? Huw miij iri latlify onnclTa uul 

warm air luccnili f 



jreniODS OF VENTILATION. 



219 



ai-e assembled, or in which numerous lights ai'e burning, when 
we (ind that it is filled with a hot in-espirable gas which al- 
most suft'ocates us. 

In order to allow this vitiated air to escape, an opening 
shoidd be made iu the upper and another iu the lower part oi 
the room.thTOugh which cold jmre air may enter, to take the 
pljice of the hot air as it passes out at'the upper opening. 

It is the neglect to provide the second opening that usually 
renders attempts at ventilation so unsuccessful, for the wann 
air can not pass out with any freedom unless there i« ample 
pi'ovision for the introduction of fresh air to fill the vacuum 
caused by the escape of that which has become vitiated. 

The openings described above are usually connected with 
tubes or flues. Tlie flues, intended to aftbrd a passage for the 
vitiated air, should be built in the chimney, Jn order that they 
may be kept warm, and thus insure a steady ujiward cun-ent, 
which may aid in ventilating the room at all times. 

When a room is uot provided mth flues, excellent ventila- 
tion may be obtained by lowering one half of a window, to 
make an upper opening, and raining the lower half, to provide 
tlie lower opening. In a bedi-oum it is best to adjust the win- 
dow at the greatest distance from the bed, to avoid the Ibrma- 
tion of draughts, which may produce rheumatism and other 
diseases. 

The various methods of warmini^ houses are intimately con- 
nected with the subject of ventilation. They may be divided 
into three classes: Ist. By open fires; 2d. By stoves ; 3d. By 
furnaces. 

In the method by open fires, either of wood or coal, there is 
an enonnous loss of heat and consequent waste of fuel, more 
than nine tenths of the heat produced by the combustion pass- 
ing up the chimney, and only that portion which radiates from 
tlie ti'ont of ^he fire }»eing utilized. Auother disadvantage is 
the production of draughts or cold currents, which flow in 
thi-ough everj' cranny and creWce to fill the ^'acuuni caused by 
■e passage of the heated air up the chimney, and which must 
^^tt in Older that the conilmstion may go on. 
^p^e advantages are, 1st. A partial ventilation, since the open- 
ing of the chinuiey is in the lower pai-t of the room ; 2d, The 
warming of the air without burning the fine organic dust 

mgH are re<|aired in order l< 



Ilnx mnny o|> 
ritOBlciL? Hoiir 

arc cmjiloieil in wnmin); liauAes? What nro the 
open fii-cs ? What are the ailvntitages nlicmling Ihi 



n. ruiim, Bud where slioultl thry ha I 
ividrd with flncH? Wbnt mcilind* j 
:iona Ig ibe melbod of wartning t^ ] 



220 



METHODS OF WAllMINO. 



which floats in it; but these are almost TOunteracted by the 
fact that one is obliged to keep continually revoh-iug in front 
of the fire in order to be wamied equally. 

In the second method the fuel is economized, and, if a long 
pilje 13 attached to the stove, the greater portion of the heat is 
utilized ; but the disadvantage is the bnrniut; and charring of 
the tilanieuts of organic matters that float m the air of the 
room, whidi renders them more iiritatiug to the delicate imi- 
cous membrane of tlie lungs. The ventilation obtaine<l by the 
stove is also impeifet-t, since it draws the air from the parts ad 
jaeent to the floor, and allows the noxious gases to accmnii' 
late, It also has a tendency to render the air veiy dry, which 
should always be counteracted Ijy keeping a vessel of water «D 
the stove, that moisture may be supplied as fast as it is i* 
(juired. 

The objection regarding draughts also exists in the use of 
the stove, but to a greater extent. The temperature of a room 
warmed by a stove is highei- than that of one warmed by an 
ojien fire ; since, therefore, the variations and contrast* are 
greater, the consequences are more severe. 

Under the method of warming Ity funiaces we may cla.'iMfy 
tlie orilinary hot-air furnace, the coil of steam nijies in a room, 
and the hot-water or steara-li eating t'nniace. The ordinary' hot- 
air furnace has many advantages over the method by ojhjh 
fires and stoves; among these, the chief is the avoidance of 
draughts, the tendency of the furnace being to condense air 
into the room, and so destroy all ojiportunity for the formation 
of draughts by keeping continuous currents of warm tur flow- 
ing out at every crevice. 

The hot-air furnace also provides the means of obtaining & 
most thorough ventilation by continually renewing the air con- 
tained in the apartment. The only valiil objection to this sys- 
tem of warming is the liability to render the ai;- irritating to 
the lungs by burning and drying it. This may be avoided to 
a great extent by jiroper attention to the condition of the fur- 
nace, and supplying the hot-air chamber freely with watCT in 
shallow pans, m which cloths are suspended, tn provide au ex- 
tended surface from which evaporation may take place. 

The use of steam pijjes in rooms for the jiui-pose of wanning 
is the worst of all methods employed. It is true it is couven- 

Whni ia iho nJvantngc piitinl by wsrmmg witli n siovp ? Wlmt nro ihc diMuIvanugn 
of (he second mcihoj ofivai-mitief How eliunld the dninKofthc nirbe rcni«died? Whai 
nre llie BdvNnUi;ei ntrendinf* ihc line of the liot-nir famiico ? Wlinl aro iho duadranTocvf 
How mny llic; bo rcciilicd? What ia tha wont system of wanniny? 



WARMING HY FURNACES. 



221 



lent, economical, and cleanly, Imt nil these advantages are nulli- 
fied liy the abwtlute want of ventilation which attends this 
system. The air of the room is never changed, but is -warnied 
over and over again, i-ising to the top of the ehamber, and then 
passing over the heater when it has become cool, to be again 
heated and breathed, so that" on entering such an apartment 
one ia nauseated ^^dth the foul odors that pervade it if it con- 
tains many people. 

This method may answer very well, and be used with im- 
punity in stores and shops where the doors are being continu- 
ally opened and ti'esh air intraduced, but it should be abol- 
ished from hiispital wards and small bedrooms as being pois- 
onous, unhealthy, and not to be tolerated. 

The last method, by the hot -water or steam fiirnace, in which 
the air is warmed in a chamber filled with pipes, through 
which steam or hot water is passing, is the best of all the sys- 
tems employed, since it coml)me9 alfthe advantages of the hot- 
air furnace in regard to the avoidance of draughts, and at the 
same time warms the air ^nthout scorching it. 

We can not leave the consideration of the subject of ventila- 
tion without drawin" attention to the manner in which the hu- 
man 8y,stem gradually adapts itself to the increasing foulness 
of a confined volume of air. An e.\ample is aflbrded by the 
maimer in which a number of men will congregate together in 
a room void of all meanK of ventilatiiui, and continue to Finoke 
and diink for hours, with the windows and doors closed, until 
the accumulation of foul gases is so great as to produce almost 
immediate faintness in a person who eutei's the apartment from 
the exterior fresh air, ivhile those who have been present from 
the commencement of the orgie seem to be unaffected. 

Though the system may adapt itself to the use of a vitiated 
atmosphere for a time, it is evident that it must result finally 
in reducing its tone and vitality, and favor the development of 
many diseases. It is doubtless owing to the unavoidable im- 
purities in the air of great cities that the inhabitants of such 
places do not live as long as those who reside in the country, 
and breathe the pure fresh air of the woods and fields. 

g. Undff wlmt circiLtnsluneeB niny Ilio meihod of wanning bv sream loila in rooms bo tni- 
" fed? Whnt is thobcBtraetJioJ of warming? Cnn (he ajatcm ncio|it iWelf lo the aw of 
Whatii one ofilic chief caiuet of Ibc shortness uf life in dlics? 





CHAfiCOAL AS A DISUTFECTAST. 



LECTURE XLVI. 

DISINFECTANTS AND SIALARIA. 

_. employed a» DisitiftctanU. — The Peloponneaian J^agttt^, 

tion of Charcoal. — Malaria or Miasma. — Circuinglances under icAiVA it 
ia produced with greatest Virulence and Eapidity. — la not the JlauU "f 
Animal or Vei/elable JJecomposition alone. — JSvils attending the ehtt 
Proximitt/ of Trees to a Dieellinff. — Selection of a Sutlditig Sit(..—Iitk- 
live Power of dry and moist Air to convey Malarial and other £ntinia- 
tions. — Explanation of the Appearwice of Malarial fioere on AiflA 
Ground. — Means for warding off t/ie Aece»» of Malaria. — Eff^t p/ 
Change of Air on the System. — Action of Winds. — Time at trAirA a 
Consumptive skotdtl IVavel. 

When the air of a house, or given locality of limited extent, 
has heeome impure from the presence of uecaying animal or 
other organic matter, it may often be purified by the use of di*' 
infectants, such as carbolic acid, free chlorine, the chloride cf 
lime, or the solution of chloride of soda. Ou the gi-eat Rcali^ 
charcoal ia the best <liainfectant, as was demonstrated by th* 
fact that the great fire in London put a stop to the plagi 
which was raging at the time the fire originatetL It la aH 
the oldest kno;m disinfectant, for we read that in the year B.C. 
430, when, by the Peloponnesiau War, Athens was crowded Avith 
fugitives irom the cities in the vicinity, a great plague broke 
out, which Hippocrates stopped by causing immense fires to be 
lighted in all parts of the city and its \-ieinity. 

The disinfectant power of charcoal is probably due to llrt 
property it possesses of absorbing different gases. Of aimno' 
niacal gas it will take up ninety times its own volume ; of hy- 
drochloric acid gas, ninety-five ; and of other gases various pro 
portions. Since the deleterious poisons of fevers and ])laguea 
exist in the gaseous state, or are disseminated through the sir 
in an exceedingly fine state of subdi\'ision, it is reo-souablv to 
suppose that (."liareoal removes them by absorbing (hem into 
its pores, just as it absorits hundreds of other gases and vapin« 

The terrestrial emanations or malaria, which are generally 
supposed to produce fever and ague only, but which really po» 

Nntno llio >at»Mnc« vniiitii.rcil as dbinri-cinni*. Kow did Ht|>p<>i-niir> Mnp (Iw pUfM 
tlini fallowed tho I'ldoponni^iiBii Wnr? Toirhai [jropoTIxof charwnlU ita ilininrMani iv* 
cr duo? What name ii circa to ibo tcrrcitnal cmaantioiu ihai produce fvvcr and agnt* 



OKIGIN OP SUASMATIC FEVERS. 

the power of modifying, and even of originating many < 
i»e diseases to which man is heir, and giving them a ])erio<J ^ 
&aracter, are still t-nveloped in mystery. They are generally 
iroduced in manih districts, but they also appear at times in 
olcanie regions which ai-e j>erfectly tree fi'om marshes, and do 
lot even contain springs or any other nntural waters. It is 
(apposed by many that the malarial poison is the product of 
flie ilecomposition of vegetable substances; ljut,if the presence 
irf vegetable matter is necessary, how are we to account for its 
Ippearance in volcanic regions where there is no vegetable 
iatter for miles I In marsh lands the malarial poison is most 
itense in its virulence when the water has all disappeared, and 
he bed of the marsh so dried up that all decomposition must 
ive ceased ; and experience has taught that it^ in the very 
orst regions, the ponds and rivulets are kept full of water, so 
'hat their beds are not exposed, there is very little danger- 
there can be no fouler odor or miasm than that which eraa- 
lates from the hold of a sugar-ship, and yet it has never been 
known to create miasmatic tever. We might continue to cite 
tumerous other instances to demonstrate the fact that the ma- 
uial poison is not the residt of vegetable decomposition alone, 
tut, aa our space will not admit, we pass to the considtiiitton 
irf the theory that it is the picxluct of animal putrefaction. 
If miasmatic fever was caused in this manner, it should be 
lost intense in the vicinity of the establishments occupied by 
knackei-s," who are engaged in converting dead animals into 
rtich manufactured aiticles as ammonia, but we do not find that 
iven the " knackers" are predisi)Osed to malarial diseases ; on the 
wntrary, they are usually strong and healthy in spite of the vile 
wilors among which they live, and many reach the advanced 
ige of eighty. An epicure -n-ill eat the flesh of a bird that is 
Blitrid, and yet no symptoms of malarial fever appear. Medi- 
iai students will breathe the offensive air of the disseeting- 
foom for months with peifect impunity. We therefore are 
Iriven to the conclusion that malarial feveni are not caused by 
nimal exhalations alone. 

From the statements made in the preceding paragraphs, we 
(ee how imperfect our knowledge of the origin of miasmatic fe- 
'ers is, yet there are certain welWstaVjlished facts regarding 
hem wnich are presented in the following ([notation from one 



In whiit kini) of soil ilo liny prevoil to ihc crrntiat cuicnt ? Ik n mnrkliv noil 
I dcTclopmcTil ur mnlnrin ? Is iho malorinl puiacin tlic product of vegplnblc <lc<^i>Tnpn»il 
ino7 At n'hnt time iloca mnrah land cralvc malnrin Willi (lie granlrst '" ' ' 
la prtKlaccd bj nniniol dcconipositioD? 



J 



224 COKDITIONS FATORABLE TO DEVELOPME>'T OF MIA^M t 

of our most distinguisheti nui-dioal authors: "It may be etatwl 
■ as a ffeueral rule that houst;s in confined, shaded situations, 
with damp courts or gai-dens, or standing %vater clast: to thfiii. 
are unhealthy in every climate and season, l>ut espeeially in a 
country suhject to intennittent fevere, and duiing the fcuninicr 
and autumn. In our own country nothing is more common 
than to see houses built in very unhealthy situations, it ft-w 
hundred yarda-ilistant only fi'om a good one. Again, bonnes in 
places otherwise unexceptionable are often so closely overhung 
with trees aa to be rendei'eil far less healthy residences than 
they otherwise would be. Thick and lofty trees in tlie imme- 
diate vicinity of a house tend to maintain the air in a titate of 
humidity by preventing itafree cijxndation, and by obstructing 
the fi-ee admission of the sun's rays,- Tiees growing againut 
the walls of houses, and shrubs in confined places near dwfll- 
ings, are injnnons also, as favoring humidity ; at a proper dis- 
tance, on the other hand, trees are favorable to healtn. On 
this principle it may be undei-stood how the inhabitants of one 
house suffer from rheumatism, headache, dyspepsia, nervous af- 
fections, and other consequences of living in a confined humid 
atmosphere, while their nearest neigldiors, whose houses are 
more openly situated, enjoy good health ; and even how one 
side of a large building, fully exposed to the sun and to a free 
circulation of air, may be healthy, while the other side, over- 
looking dam]) shaded courts or gaixlens, is unhealthy. The ex- 
emption of the central parts of a lai^e town fiom these fevers 
is partly explained by the ilryness of the atmosphere which 
prevails there, and the comparative eriuality of the tempera- 
ture. Humid, couiined situations, subject to great alternations 
of temperature between day and night, are most dangerotut. 
Of all the physical tpuditit-s of the air, humidity is the most in- 
jurious to human life ; iiii<I tlioretbre, in selecting situations for 
building, particular regard should be had to the circumintaficBS 
which are calculated to obviate humidity either in the soil or 
atmosphere in every climate. Drj'uess, with a free circulatitm 
of air, and a full exposure to the sun, are the material things to 
be attende<l to in choosing a residence. A [)erson nuy-, I Ixs 
lieve, sleep with perfect safety in the centre of the Pontine 
Marshes liy having his room kept well heatetl by a fire during 
the night." 

In nlint siruaiionB it tnakriu uiiinlly fau 
it? Iluvr do lliey net? Arc Irecs at n ilhl 
ulftrlj noticed In wicctine a buUiUng-site ? 



CONVEYANCK OF MIASMATIC POISOTJ". 225 



1^9 cxlorous \'arMira and gast^s are conveyed to a greater dis- 
ce by moist au- than by that which is dry, so, during the 
day, the miasmatic exhalations are conveyed in the atjueous 
vapor that arises fiom t)ie soil in which they have l)een gener- 
ated; and at night, when the vapoi-s condense, the miasmatic 
poison is also dejxisited, and accumulates in the strata near the 
surface of the earth. Tlie lower storie?'. of a building are there 
tore rendered very unhealthy if the windows are allowed to le- 
maiii open duriiii^ the night, while the windows of the upper 
stories may be left upeii w itii in]]tunity, since all the malarial 
emanations are condensed in the lowest strata of the atmos- 
phere. In all dangerous districts it is unsafe to sleep on the 
lower stories of a house, and it is best in sdl localities to have 
the bedrooms on the second or third story. 
^tBy the action of winds, miasmatic poison may be carried to 
^RLsiderable distances ; and it is found, as we might naturally 
llpect, that any thing that tends to break the force of the 
wind, or turn it from its coui-se, is a protection against malaria. 
The presence of a high wall or screen of woods is often an im- 
]».issable bairier to such emanations, and even a low hedge of 
imshes wUl frer|uent]y turn them aside, and render localities 
healthy which would otherwise be uninhabitable. So perfect 
is the protection aflbrtled liy fringes of bushes iuid forests, that 
some suppose the leaves possess an affinity tor the malaria, and 
filter it out from the air in which it is being conveyed. 

• CHANGE OF AIR. 

Our pliysieians frequently prescribe a change of air as a 
Biedlal agent; it is also one of the best hygienic stimulants 
at can be employed. When the mind and body are reduced 
by overwork, a slight change from the city to the country, or 
even fi-om the country to the city, wUl often produce the most 
marvelous improveuieiit in the general heallli, and reinvigorate 
all the organs of the system to such an extent as not ouly to 
ivard oft" an attack of illness, but even enable us to undergo m 
creased labor, I>y funiishing a new lease of life and vigor. 

The advantages of a short styourn at any of oui" watering- 
places are well known, but the majority of people seem to 
think they are chiefly due to the nauseating M-aters that are 
always in the fashion at such plat;es, whereas, in reality, the 

One* moist or ilry nir convey ujomii* emniialioiiH tn iliv cn-aicst lii-tiancc? Whv aro ilii! 
lower irorius (if n iiiiUtliiig the inoti iinliviillliv ? 
mnlBrial fi'vors on tiiitli Bfiini'? iif" '"uy 't"i ■ 
Wliit U llie (iffi-d ori:baiigo of uir on tliu svaicm; 
P 



226 



EFFECTS OK CHANGE OF AIR. 



salutary results are in a great measure tlie effect of change of 
au', anil the continued succession of gay scenes and pleasurcfi 
into which the invalid is oMijred to enter to a greater or Icffl 
extent, and which, liy divertin-r Ins mind, give it rest, so Uiat it 
can recuperate , uud with the inijirovemeut in the tone of the 
nervous system, there is necessarily impi-ovenient in the gtneral 
health. 

The effect of ivinds is very similar to that of change of air, 
for they substitute a pure atmosphere for that which is stag- 
nant and laden with poisonous emanations. 

When the system is already prostrated liy a slow, lingering 
disease, like consumption, great care should ne taken in the se- 
lection of the locality to which the surt'crer should go. It i» a 
very common idea that a ti-ip to Snulliern Kurope, and a so- 
journ of a few months imder the soft Italian skies, is one of 
the best things that can be done; but, though it may be of ail* 
vantage in the earliei' period of the disease, it too 4)ften hastens 
the flual catasti'ophe iu the latter stages, the separntion fnnu 
the comforts of home, and the absence of those who could cheer 
and comfort the sufferer producing more lianu than the change 
of air does gootl. 

Certain islands have been long recommended as comluning 
many ad^'antages foi' consumptives ; among them we may men- 
tion Madeira and the West Indies. In many cases great ad- 
vantages are derived from a sojourn at these jtlaces in the vnv 
ter; but the evil consequences of removal lu the latter stages 
of consumption are marked in the chure'h-yards by the tomb- 
stones that indicate the resting-places of those wlio sought re- 
lief when it was too late. 

To what cnuscs miiv mi 
pldPC t now dg winils ni 
pnticnt tmvcl? 




EFFECT OF EXTKEMES Of TEMPEBATUEE. 



LECTURE XLVn. 



HYGIENE OF THE 



! of midden Change« of Tetiipfrattire tni Me Martalitif Liata. — S;/mp- 
( of aj^iroachiiig Death fi-iim Cold. — Soul/iern Nationa resiat CM 
IT than NortlitTii. — Tuue at which it ia best to go into the coUl Air 
t heated Itoom. — l^'ect of Moiature oh th« Hgstem. — Effect of 
ccated Air on the Miicotia Membmiie of the Litnga. — Grtul solvent 
t of moitl Air on Jinanationa. — Application of IFeat to Jhaen 
.—Chilblain.— Effect of Climate on JVationa.— Effects of Light 
' and Electric itg on the Bod;/. — Coitvei/ance of Miaattiatia Emanatiatia 
by damp Air. — Effixta ofWinda on emlemie and epiJeinic Diteaaea. 

ExTHESiF-^ of tempei'atiire are very unfavorable to life, the 
intense cold of winter inci-ea-sius; the mortality list among the 
M;e(l, while the heats of niidsiinimer are esiiecially fatal to 
young people and children. Barou Larrey, who was Km[)0' 
Icon's snrgeon-in-fhief during his campaign in Russia In 1M2, 
-states that dnriiig the nights of the Sth and llth nf Dccpniiicr 
the tlierinonieter touched — '27° and —83" Falivenheit, ami the 
men and hoi-yes were struck with stupor if they took the slight- 
est repose, and died in great numbers. Many of the soldiei's 
(lietl while on the niaix-h: in these instances the countenance 
first became pale, and assumed an idiotic expressinn ; sjiccch 
was imperfect and labored; the eyesight was diniiiieil.iuid oft- 
en entirely obscured, but they continued to niarcli along in e(il- 
umn, supiKtrted by their conu'ades; gradually the movements 
of the mu-irl'S l>ccame more aud more feeble; they staggered 
as though they were inebriated, and, leaving the column, soon 
fell into the suuw, whence they could not rise, but, being at- 
tacked by an overwhehning stupor, died in a few minutes. 

The same authority states that the soldiers from Southern 
Europe withstttod the cold far better than those from Germany 
nnil iSortheni Europe, the former having a higher hygienic 
morale thiui the latter, who were specially liable tf> nostalgia, 
Of home-sickness, which is doubtless caused by the domestic 
habits of the Gei'inan.-<, and all races that live in cold climates, 
and which ai'e powerfully influenced by their liom_e associa- 



Iwtii 
rfii 



CHANGE FliOJI IIEAT TO COLD, 



tions, since they are obliged to rely to a gieater extent on thtii 
fatiiilies for tbeir Imppiness and comfort. 

Vanous opinions are held i-egardiug the efl'ect of sudden 
flianges of temperature on the system, and many persons haltit- 
ually wait to get cool l)etV)re they pass from the hot atmo?- 
phere of a bait-room to the cold extenial air, fearing that tha 
sudden change will be injurious. It is tnie that there U tvn- 
OU9 risk in exposing the Ijody to a gi-eat decrease in tenipera- 
tui'e, often in the winter from 80° in the ball-room to near ihe 
zero of our scale in the open air; but we must also remember 
that if we pass into the air while the excitement still continues, 
the powers of resistance are greater than when all such Htiuiu- 
lu3 is lost by a continued lingering in the dressing-ivoni in or 
der to allow the temjieratur? of the body to fall. We can not, 
therefore, doubt that it is best, on leaving the ball-room, t" 
dress warmly, with as much haste as possible ; and if we arc j* 
fortunate as to have cheerfid company on the way home, there 
is but little danger to be feared. In no part of the world i« 
the effect nf excitement in enabling the system to resist cold 
better known than in our own vicinity. IIow rare it is for any 
one to take cold when they have indulged in a sleigh-ride; 
the excitement of the rapid motion; the joyous jingling of the 
bells; the merry song and merrier laugh being contagious, nud 
producing a degi'ee of stiniulatitm that is a pi-otection agmnst 
the evil consequences of what would otherwise be a dnngcrotis 
indulgence. 

Though sudden changes from heat to cold can be borne witli 
comparative impunity, tliose i'rom cold to heat are very apt to 
give rise tu injuiious ninsequences; and when the body, or any 
part of it, has been chilled, the application of heat should he 
gi'adual and cautious. The chilblain is not produced bv thp 
action of cold, but by the cftcct of heat on the chilled exln-m* 
ity. Sometimes the inflammation runs so high as to tenninate 
in gangrene: such evi! conse<pieuces may be avoided liy apply- 
ing heat gradually, the be.'-t method being by friction with 
some cold substance. It is saiil that in the north of Eui-opc it 
is not an unconmion incident for a traveler to be surprised in 
the winter season by a stranger rusliint' up to him with a hand- 
fill of snoM', and proceeding to rub his nose in the most dis- 
courteous and vigorous manner, in order to restore the circula- 



Al wlint limn i» ii bosl lo roiurn liomc from n bntl ? Whj i« ii ihkt peojilp so ntnit hke 
mill whilo nlpifb-riilini;? h a «ii(l<lpn rlinnp: rnitii licnt lo oiiU ta dali|;eivii> n* tma flw 
cvtd lu heni? How &lioul(J hcut be u|rplii'(l 10 a fr ~ " ' ~ 



r 



EFfECTS or LIUIIT AND ELELTlUt'ITY ON HIE BODY. 229 



tion in the frozen feature. Even in Neiv York we occnsinnnlly 
Lear, in very cold seasons, of pt-rsous who have lost their teet 
or handd by applying heat iucantiously to these members when 
they have been tlioi-oughly chilled or even fi-ozen. 

Ill the teniptrate regions the c^hanges are more fi-equent and 
viitleiit than in i)tlier climate'', and we find the impi-esH of the 
climate stauipeil on the character of the nations of the temper- 
^ate z<)ne. As their climate is variable, so they are snhject to 
^■Kpid variation in thought anil action. They are compelled, by 
^Ble exigencies of nature, to meet sudden vanations with suit- 
^Eble remedies, and, from a mere attention to the means re- 
quired to render existence tolerable, they 1 'V de^rcew cairy a 
Hystem of observation and experijueut into, all then' affairs, and 
^i)asa their time in unceasing activity, whih' tht- inLabitant of a 
Hnore tavored clime is wasting his life away in dreamy idle- 

^i It is not only necessaiy that fi-esli air should be freely and 
abundantly sujiplicd, for light is also essential to the proper 
di;velo]»iiieiit nf ilir body, as auy one may satisfy himself by 
comparing tlip blanched, sallow, deformed child who works iu 
mines, with the robust, ruddy, well-formed little one who has 
his home among the green fields, and spends hours playing iu 
the sunshine. 

The electric state of the atmosphere also influences the sj'S- 
tem, and though we may not be able to trace its method of ac- 
tion, we all know how the jjliysJcal and mental sensations are 
iiitliieuced by an approaching stonii. The effects of the sudden 
<listii;irge of a large amount of electricity on or into the body 
is also well known to result in almost instantaneous death, and 
the bodies of persons who have been struck by lightning un- 
dergo decomposition more rajiidly than those of peigons who 
have died from other causes. 

The liygTometric condition of the air also exerts a powerful 
iutiuence on the condition of the system. Air at all tunes con- 
tains moistin-e, which may be detected by Vinnging it iu con- 
tact with a cold surface, when the vapor of water immetliately 
condenses, and covers the sniface, as, tor example, a pitcher of 
ice-water, with (iropa of moisture. 
~~' I have shown by careful experiments that a large projMjr- 
pn of the egesta escapes from the body in the form of insensi- 

Uow iloTB Ihc i;lini]ilc of the lemperiilc zone nffcci llic inhnLimnls of ihaL roiriun? Hnw 
HliKhlnffect lliu body? What is llic rfltd of n 'adilcn disflinrgo nf elpnririly on itio 
W? Haw Jdps thu liv|iroinelric alaic oftliu uirafiuct tlicboily? Howb ilio pR»enca cf 
Mue in the air dulei'ieij? 



•230 



CONVEYANCE OF EMANATIONS BT DAMP Allt. 



ble perspiration or vapor. When the air is laden vnth moist- 
ure it can not so leadily take up the vapor trom the skin, and 
we t;()nseijiieiitly feel the heat more severely than when the 
ilcw pcjtiit is low, and there is less interference with the vajxir- 
izjitioii of water imm the system. Under these circiirastances 
there 13 a. tendency to the accumulation of effete materials in 
the hody, and consequently a greater liahility to diwase. 

tiay-Lussac found that at gi'eat altitudes the projxirtion of 
moisture in the aiv steadily decreased, and reei])iration is attend- 
ed l>y disagreeable sensations, caused, as he supposes, >iv the 
desiccating action of the dr\' air tm the lungs. A moist air linn 
a greater solvent artion over various mineral, vegetJihle, and 
animal substances than a dry- one. In bui-niiig lime the work- 
men find that the carbonic acid gas is displaced with gn'ater 
facility OH a damp day than on one which is drj'; they come- 
ijueutly jilace in the ash-jnt of the furnace a pan of water, tlif 
steam from which, pj^ng into the iire, aids in expelling the 
carbonic acid. The mineralogist avails himself of the ^*«nle 
property of moisture when he causes the various elaj'dike holl- 
ies to give out their peculiar odor by breathing on or moisten- 
ing them; and all must have noticed the great dijutance t« 
which foul o<lors ai-e conveyed in a fog, or just before a rain- 
storm, when the air is highly charged with moisture. The ma- 
larial emanations from the earth are also in many instancts 
carried to great elevations by the moisture that ha'^ been evap- 
orated by the sun's rays, and after passing over many miles of 
level land witlmut i>rodueiug any evil consequent-es, are finally 
dejtosited on the high lauds from the water that is comlensed 
in these legions by the deci-eased temperature that pi-evaila, 
and give rise to agues and other malarial diseases. This is m 
well Known that the inhabitants of malarial districts reganl 
the time at which the dew falls as the most dangemua, and 
carefully abstain fmni exposing themselves to its action. 

It is said that in Africa, when the diy wind blows fi-om the 
interior to the ocean, not only do the oixlinan' endemic diseases 
leave them, but those which are epidemic m their character, 
and even contagious diseases, as small-jiox, also disapj>ear. If 
this is true, ami there is no good reason to doulit the veracity 

Iluw lines 1I10 nir of i-reHt nliltiirlci nffcrt llic rrBpirnlorr B|ipnmtii»? What «n»0*J- 
Lunsnc's llioory of iis modo of nciii)n ? Uutb iiioijl ur Jry nir |«sjct» ilir umitcia toltttd 
pDwrr orar cmnnnlinns? Wliv is wnlcr plnnul in tlio [til if a limo-kiln ? Uirc illuiunlinot 
i>rih(>lio«eruf ninisl nir locoiivoyodur* Willi BTFnWrrntilil; limn ilry nir. Iluw rio ni*h- 
rinl piiimmiiim* rewli Brent clerniions? At ivhnt time cif tin' ilny i> malnriu nicnii ilni^n^ 
oui? Wbnlia (lie ulTcct of ivimli on enilcmic anilrpiJriDicduicaiHa! 



TItK ROMAN BATHS. 



of the statement, it would appear that the humidity of the mr 
influences tlie pmperties of diseases, i-endenng them more dan- 
" [erous in some seasons than in others. 



LECTUKE XLVIir. 



JonditioTiii esanitial for t/ic proper Comhiction of the Action of the SKin. 
fc' — The Jioman ITiernifB- — Action of pure Water oti the Skin. — Cse of 
ip, — Abiiae of Sotip. — Vokl jHnnatfialfi, — 7?ie (JhUl or Shock. — 
I of the CMJiathfor Iiifaiita.— Vuii(litwna of the Sifst^i in tr/iick 
i Coltl Batiti ahotilil not be used. — Tepid Hatha. — AdajHafion of TepuJ 
m Jialks to various Constitutions. — Warm Births and their Action. — Hot 
\ji(Uhs and t/ieir Action. — J^lai;ellalion.~~lS/Knnjxioiiti/. — Turkish Bath. 
t, — Sea Batliing. — Effects of the lonff-conlinued Application of Water to 
Jlhe iS&in. — JSail Consequences attending the sudden Stopj>age of the Ac- 
ftlonofthe Skin. 

I TuE skin being one of the great excivtory organs of the 
totly, it is necessary that its function shouhl be discharged in 
i proper manner, iu order that the sy.stem may be relieved of 
tlie deleterious substances which escape through the cutaneous 
glands. The hygienic conditions to be observed in oi-der to 
acer>m])Hsh this i-esidt are a due regard to cleanliness, and the 
proper pmtectiou of the body by suitable clothing. 

It is .'laid that we may judge of the degree of civilization a 
nation has reached by finding the per capita amount of soap it 
consumes. This may lie veiy true as regards civilization, but 
it is not necessarily the ease regarding health, for we may abuse 
the proper use of soap and of water to such an extent as to pro- 
duce injurious conserpiences. 

Among the Romans the bathing establishments were very 
magnificent, and contained the frit/ iJan'iim, or cold — the cahhi- 
i-inDi, or hot — the teplihtriiiiii, or wai-m — and the rapDranirm, 
or vajior liath. They were also provided with the coxa-Jiifiiim, 
or hip bath; the inauvhirinii}, or hand batli ; thejml/hnninn, 
or toot bath* the citp!tiihiriii»i,oT head bath; the Htmicvpiuni, 
nr half body liath. ^Vc cinjiloy, in addition, the shower-bath, 
electric batii, the dry bath of hot ashes and sand, and finally 
the animal bath, which consists in \n-ap]iing the wann skin of 
a recent ly-kil I wl animal around the body. In their great Iher- 
M^a£B, or baths, tlie Romans also had the apinUterium, or dressing- 



232 TUE EFFECT OF PLLKGK AND SUOWEU ItATIIS, 

rooraa ; the nnctunrivm, or pei-fiiming-rooiii ; and a host of serv- 
ants, wh') pfHornied special diitiffi in the various apartment*. 
. So solid ami dnral)le weie the tJievuiEe, that in many cities they 
constitute the liest jneserved and most interesting ruins : they 
have alsti yielded to the modern museums many of the fined 
speL-imens of ancient art, the majority of the famous pieces of 
sculpture and mosaic having beeu found among the dehris ol' 
the Koman Imths. 

Water is the jii-oper fluid to be used in Mashing the surface 
of the I'ody, for it removes the soluble excretions of the cuta- 
neous glands. Soap is also admirably adapted to the removal 
of dirt of every variety that may have accumulated on the 
hands or teet; but if it is utjed Uto freely on the general sur- 
face of the body, it diifsolves the oily exudation of the seba- 
ceous glands, which is required to enable the skin to retain its 
flexibility and softness. The external epithelial cells are also 
i-enioved t(X) rapidly when soaj) is used in excess, and conse- 
quently the skin is not properly protected : it becomes subject 
to greater congestion in oi'der to reproduce the cells and oils 
that have been abstracted, and is therefore more liable to cause 
disease in the eystem when it is siuldenly subjected to the ac- 
tion of cold or dmughts. 

The cold plunge or shower-bath is the best form in which 
water can be ajiplied to the whole suiface of the body, when 
the system can bear the 8h<)ck ; it then i-emoves the soluble 
salts that have been delivered on the suifaee by the sudoripa- 
rous glands, accustoms the skiu to the sudden application of 
cold, and gives a healthy stimulus to its action and to the 
whole system. 

Since the temperature of wells and springs is usually below 
60' Fahrenheit, and that of the human bo<Jy is about 100", it 
is evident that the cold bath, in its first application to the !•u^ 
face,nuist abstract a lai'ge amount of heat. The effec-t of llus 
loss of caloric is the production of a chill or shock, in which 
the skin is shnmken and bloodless, the internal organs over- 
loaded witli lilood, the nen-ous centres rendered toi-jiid and 
sluggish, aiid a general sedative action produced. If, on leav- 
ing the bath, tlie ]>crson stejts into a warm room, and the l»ody 
is quickly niljbed dry, reaction comes on ; but if the bather w 

What is tho nciinn arptirairnter on the shin? Whnt is the olijeci of iiiJni; taa.\\l W)nl 
» thecfTect of em [limine nn cxcths ofsjniJ? How Jof« ihc Cold |i1uni:e.ltalh net? Wlal 
ii ihr lempcraturc of f)irinB nnti'v comimred teith thnl of Ihc skin? IVhui cgnditiotw ukbiI 
Ibc proJiictiim of r chill or shnck? How ehould (lie renrtioii Iw brought on ancra tnU 
bath? 




THE USE OF COLD BATHS. ^OO 

the Open nil', and especially if the water is allowed to evap- 
rbrate fi-om the suiface in u furrent of cool air or wind, the chill 
produced will often overiwiwer a weak jwrsoii. The tempera- 
ture and circii instances under which a bath is taken must 
therefore be modified to suit the condition of the bather, and 
cold baths should not be employed unless reaction conies on in 
a satisfactory manner when the body is speedily nibbed dry 
after the bath. 

I, Many persona think that young infants should >)e haitlened 
by giving them cold baths and exposing tlieni to cohl air. If 
p child is strong and healthy it win stand a degree of exjxisure 
ilrith impunity, but if it is weak or puny such treatment is 
fenminal. In the words of John Bell, "Cold bathing of tender 
infants, without regard to constitution and temporary changes 
of health, acta in a manner nearly analogous to the test of ni- 
tne acid on the metallic alloys: if gold be in them it remains 
untouched, and is exhibited in its native brightness ; the other 
metals are corroded and dissolved. So with the cold bath; the 
feeble and valetudinary sink under its use, while the strong 
and robust are exhibited in a more distinct point of view, and 
* TTe even benefited by their acqulnng a habit of endurance of 
old," 

In those who are suffering from acute cutaneous eruptions 
he cold bath will often pinve injurious. Those persons wlio 
oe subject or liable to sudden internal congestions should 
ivoid the use of the cold bath. Women also, at certain times, 
ihoiild, as a rule, Ite very careful in the exposure nf their bodies 
the action of cold. 

When the cold bath is followed by a healthy glow over the 
ivliole body it may be freely used; but if it produces a chill, 
which continues even though the body is well rubbed, it 
should be avoided, and tepid or warm batlis substituted. Tep- 
id baths are sometimes debilitating in their action; but since 
them are certain constitutions which can not bear the sudden 
application of cold, the use of warm water is sometimes neces- 
sary tor the purpose of cleansing the suiface of the skin. When 
tejiid baths are employed, the time the person i-emains in the 
bath should not be more extended than is required to wash 
~'he surface of the body. 



i 



la ilieitiiliwiiiiiinnte iifieori'nli] bnths for joung infiinis jiiaiili»Me? Slioiild ihe coM Imlli 
iHal ]•}■ ]K!rmlia aiifferiitu fiom nunlo eniptiva iliaemies? Uiidpr wbnl coiiJilinin slimilil 
I lie mill bnili be used ? Iluiv du lepid biillis act? Ilow long sliould ii )ierKoii remitin iu n 
icpid bntii ? 



234 AITION OF TEPID AND HOT BATILS. 

The tepitl batli should have a temperatiii-e from 75° to 90°; 
it is adnuralily adapted to constitutions in ^vhich the shock of 
the cold hath is injunous. It may be adjusted to all <.-on>-titii- 
tious by first immersing the body in water wLieh is ven' nt*ar 
the temperature of the system, and then cooling it five «r ten 
degi'ees, and repeating the imntei-sion; and, if it is desirablct 
the same jjrocess may be again repeated. 

The Marm bath should liave a temperature of about tt5°; 
when the circulation ia languid the temperature may be two 
or three degrees higher, and if it is active it may be a few de- 

frees lower. It is especially grateful when the body is ex- 
austcd by the fatigue of labor or travel, sintr it removes the 
accumulated secretions of the ekiii, and reiiivi^orutes the sys- 
tem without subjecting it t<j a shock. For old j)e.i]ile and in- 
fants the warm bath is preferable to the cold, and the <lnneM 
of skin from which many old people sutler is often relieved by 
using the warm bath two or three times a week. 

The effect of the warm bath on the omans of circulation and 
respiration is sedative, the rate of pulsation and respiration be- 
ing diminished, and the capillaries of the wkin relaxetl, the 
l)lood flowing with greater ease and fi-eedom to all jiarta of the 
system. 

In the hot bath the temperature of the water is above 08'; 
its action is stimulating, since it adds to the heat of the IkhIv, 
and excites the circulatory and nervous systems to an e.vtfnt 
that is often injunous. The plethoiic condition of the btxly 
under the e.\citement is showu by the swelling of the fingers, 
the rings that are worn producing an uncomtbrtable iiegi-ee of 
pressure, and such sym])toms as vertigo, paljiitation, and faint 
mg being often sujjerinduced ; these ])ass away on leaving the 
bath, and are followed by a free pei-spiratiou and a sense of ex- 
haustion. 

In some countries certain manipulations are considered to be 
necessary accessories to a bath. The Russians submit the liody 
to a coui-ae of flagellation with birch twigs in order to excite 
the cutaneous capillfiiies. Fiictions are employed by others, 
but the operation of shjiiiipooing is perhajis the most eomplei; 
it was originated by the Hindoo--, and is described as follows; 
" One of the attendants on the bath extends you uixin a lieiicli, 
sprinkles you with wai-m water, and jn-esses the whole body in 

Whr» iliouM bo [lie tiimgiernturG of a lepid Inili C [low niiiy it b3 mdjiiatrHl lo farioM 
'una? Whni should Ui [lie iPin]>uni[nrc nf ilie wnnii bntli! What » iu dTcM "a 
ni? Whni U the ti^inpemmrc of a hoi bitlli? Haw ilocn il hpiF What Mala t.f 
n fullon-s rhd hot bnih? What u Ungoltntion ? Wlnii ii Bhani]>ooii]£? 



SHAMPOOING AND SEA-BATHING. 235 

I adniiral)Ie nmniier. He craclte tlie joiuts nf tlu* fingers aud 
t all the extivmities. He then plaees you upon the stomach ; 
pinches vou over the kidneys; seizes you by the shoulders and 
vracks the spine by agitating all the vertebne; strikes some 
powei-ftil blows over the most fleshy and muscular parts ; tlieu 
rubs tlie body with a haiv {,'love until lie sweats; gi-inds douii 
the tliifk, hard skin of tlie teet with jjumice-stone; anoints you 
with soap ; and, lastly, siiaves yon, and jilueks out the snpei-flu- 
ous hairs. This process continues for three quarters of an liour, 
after which a man scarcely knows hiuisflf; he feels tike a new 
being." In Eastern countries, whei-e the use of the Turkish 
bath prevails, the bather in subjected to all the above process- 
es, and at the close of the operation the surface of the Ixidy is 
anointed witli some oleaginous substance, to protect the skin 
from the consefjuences of such hai-sh tivatment. 

Sea-bathing differs fi-om the fresh-water bath not only in 
the jiresence of saline materials in the water, but also by the 
exciting circumstances by which it is surrounded. To use the 
words of Bell ; " If we niei'ely had I'egunl to the temperiiture 
of sea-ivatei', we shoukl consider immersion in it as simply cold 
bathiug; but there am circumstances connected with the act 
\vhich niodiiy materially its eflects. Sea-bathing is uBually 
preceded by some exercise, a walk or ride to the beach; it ia 
accompanied by some muscular exertion — struggling agaiust 
the waves, or, in the more robust, by attempts to sAvim. With 
othei-s, agfun, the whole affair is attended by a dread of danger, 
which pnwerfuDy ntfects the neiTous system, and causes hur- 
rit-d bvciitliiTiLT, p:il]iIt;ition, and inci-eased rapidity of the circu- 
lalioii,all of wiiicii tend to change materially the charai-ter of 
the bath, iintl render the bath in the air, whether in the sea, or 
in river or lake water, verj- eomidex in its action when com- 
pared with the ordinaiy house bath." 

In order to reduce the effect of the shock in the bath in the 
open air, it is best to imuierse the whole body as quickly as 
possible; in this manner the uncomfortable sensations that at- 
tend the gradmd immersion of the body ai'e avoided. The 
best time to bathe is alsn a matter of interest ; the bath hefore 
breakfast is no doubt the most wholesome, since at all other 
periods the stomach is more or less engaged in the process of 
digestion. The length of time a person shtmld remain in the 

I'VhalUihe finnl niKTniion in tlio Tnrkinh liaih? How ilucs scn-liurliiiiK .liff;r from (ho 
Ul-vitlor bntli? How idht xhe shock be rednced in tiailiing? Wlml U tlic bcsl lime lo 
L . 



236 EFFECTS OF LONG-CONTIKL'ED APPLICATION OF IVATER. 

water 19 a question tbat must he detennined by evfry one far 
liiuiself, but, as a iiile, five or ten minutes is sufficient, anil tbc 
boilv should be well rubbed Avith a rough towel on coming uuL 

The long-continued iipplicatiou of water is apt to ivsiilt in 
rediiL-ing the vitiility of the skin to so hnv a degree as to cause 
nuiuenius ulueratious and boils. In some people such eniptionit 
may remove deleterious substances fiom the body, but the ex- 
peiieiice of the majority shows that they are the product of the 
debilitating action of the water on the glauds ot the skin, and 
unless the abuse of that liquid ia discontinued the most disa- 
greeable consequences may ensue. 

In some pei'sona the glands in the armpits and other parts 
of the body secrete material possessing a disagreeable odor, and 
it often happens that the attempts to remove it by the fi-ee use 
of soap and water result iu its Jnci-eased production, and the se- 
cretions are rendered more offensive. 

It must not be supposed that %ve object to the proper »ise of 
water in what has been said in the preceding paragraphs ; it is 
only intended to draw attention to its abuse, and to the iKxrul- 
iarities of the systems of some indi\'idiials, for the miyoritv of 
men are benefiteil by the use of daily baths. It is a matter of 
which every individual must judge for himself, and deteniiine, 
by e.xperiiuent on his own pei-sou, how often and what vjuiety 
of bath should be employed. 

Sudden vanations m temperature and in the dew [wint are 
apt to cheek the action of the skin ; draughts of air fi-oni small 
crevices produce the same result, while a strong Avind is often 
harmless. The sudden stoppage in the action of the skin cauMS 
the eft'ete materials which it is its function to excrete, to accu- 
mulate in the system, until finally they seek an exit through 
some other channel, such as the lungs or kidneys, and, acting 
as irritants to these organs, produce the numerous iuflaaimar 
tions ^vhich aiise from exposure and cold. 

IIow loQg should n ]ianoii rt'inain in 
npplicniion of water to tlio hkin ? Wl. 
uf tlic skill 7 What causes affect the a< 



EXPEillMENTS OF DAVY. 



LECTURE XLIX. 






rtaU empioyeil in the Mam^aeture of Clothing. — Erperimenla of 
Davy on tht cmiductirig Poteer ofvarioita TeaUurev. — Influence o/Pack- 
in;/ oti the eomhicthitf Power. — Hummer and WifUer Clothing. — U*e of 
JHannel. — J^tnptioft of the aneiint Romans from Miilarin. — Ciiptain 
Mtirraifg Bxperiiiieiitg with Flannd. — Uae of Fluin„l l.i/ the A;/-^,/ and 
Infirm. — U»e of Stockiiiys. — Chanyiny of UnJtr-rl.iihihu. — i'h'lhin'j 
t/iouhl be ieeU aired. — Scotch Metftod of airtug CloHumj. — Thf Ciil ur 
Shape of the Clothing. — Adaptation oj the Shape to (he C/ci/iah'.— Ciie 
of Coraett. — Exjierimenla of Dr. Stark on the absorptive Pwetr of Tex- 
tures ofdiffe)-eiit Colors. 

In order to enable the skin to continue its fiinction with reg- 
ularity, it should be protected from sudden changes of temper- 
ature by ineiius of suitable clotliing. The materials employed 
for this puipose are linen, cotton, wool, and silk. 

Sii' Huniphvey Davy made a very interesting senes of cxpci-- 
iments to determine the conducting power of these materials. 
The method he employed was to fill a glass flask ivith the sub- 
Btance under examination, and, introducing tt thermometer with 
its bidb resting at the centre of the flask, the an'angeinent 
was then immersed in a vessel of boiling water, and the time 
required to raise the index liquid of the thermometer a given 
number of degrees detenuined. Submitting varioua textures 
to this tefit, he found that linen was the best conductor, then 
cotton, wool, and silk, in the order mentioned, silk being the 
worst. 

Da\y also found that the closeness of packing influenced 
the conducting power by entrajiping a greater or less amount 
of air in the nieshea of the tissue. When it was tightly packed 
the conducting jxiwer was improved, M'hile loose package di- 
niini«he<l the conduttibility. In weaving cloth the textures in- 
tended for winter use should therefore be loosely woven ; those 
to l>e em])loyed in the summer should be closely woven. Lin- 
en and cotton goods, being the best conductors, are suitable for 

Wh>C miuerinis nrc cini.lojril in lliomnnnfiiciiiroiirirToiliinK? Describe (hi- p)i|wrinienn 
of Diivy on ihe crmcluding pmn-r ot ililFrrent tissiios. Wlinl is the nrJcr of tlic- ninilupims 
'ditfercnt lisHQcal* What is iIid intlueticfi of riiriiiliuti in pnckiigc on cuniliivling 
Haw ihoulil summer gooils be wavcti ? 



269 USE OF FLANNEL. ^^^^^^| 

summer use in hot climatef, while woolen and silJc goods hIiouW 
be employed in the winter season in cold eliraates. 

Many discussions have fi'oin time to time arisen as rt^anls 
the healthfulneas of various textures used as under-clotliinft- 
The oldest, most enduring, and perhaps the l)est, is linen, Wc 
find it mentioned in the earliest works, anil it is even now 
found in the cerements enveloping the njummiea that were iu* 
terred thousands of years ago m the tomt)S of ancient Egj'pt 

It is not only necessary that the body should be protectwl 
from the direct action of the variations in the seasons, but cart 
sliould be taken not to expose it nhen it has been heated hv 
violent exercise. During the eoutinuation of the exercise it 
may be exixtsed fl-eely ; but ^vhen exercise has oeosed, ami it is 
bathed with pei'spi ration, and the skin is cnngestwl, it should 
be pi-otected fi'om the injurious action of draughts and currents 
by some suitnlde covering. 

When the occupation of the individual subjects liim to fre- 
quent changes of temperature, experience has tauglit us that 
tue best material to use next the skin is wool in tlie form of 
flannel ; it protects the body from the sudden changes to which 
it is liable, and absorbs the perspiration as fast as it is secrreted 
without producing a disagreeable sensation of chilliness, as is 
the case with liuen and c<itton. 

By some the use of flannel next the skin is held in such high 
esteem titat they have even attempted to show that iu post 
times the Romans sutt'ered less from the malarial fevers because 
they incased tlieir Vjodies in warm materials made of wool, and 
it has been thought that the sheep and othfr animals that feed 
during the night on the Campagna owe their freedom from ma- 
larial disease to the dense covering of wool or hair with which 
Nature has provided them. 

The advantage of wearing wool next the skin is properly 
appreciated among army and navy officers ; and Captain Mar- 
ray, of the British ship \ alorous, relates " that he was so strong- 
ly impressed, from former experience, with a sense of the vm' 
cacy of the protection aftbrded by the constant use of flannel 
next the skin, that when, on his anival in England in Decem- 
ber, 1823, after two yeai-s' ser%'ice amid the icelierirs of the 
coast of Labrador, the ship was ordered to sail imuiettiatfly for 

Whnt i-i iha bout nmlerinl K 
skill is congcBied ? Whni h ilic bi»i mmcrinl tu wenr lu 
to be «nhmilt(Ml lo BuiMcn tlinngw i>f icm[>eriiliirc ? Wliiil n\ 
inc ihc Fxcmplinn of iho nitcirnt tiiimnn" fruni ninlnrinl fcvrr- 
of CnjiMln Murmy rceitriJiiisilio iiw uf flannel in liot and mli 



Murray's observations. 239 

the "West Indiea, he oi-ilered the purser to draw t«-o extra flan- 
nel shirts and p!iir« of dra^v■e^s for each man, and inn-titiited a 
ri-gular daily inspection to see that they were wtim. These 
jireesiitiona are stated to have been followed by the most Iiap- 
py res^ults. He jiroceeded to his station with a crew of one 
liunibi'ii and lifty men; visited almost evei-y island in the 
Wi'r-t Indies, and many of the ports on the (ridf of Mexico; 
and, ni'twitliHtandint; the sndden transition from extreme cli- 
raatcy, retunied to England without the loss of a single man, 
or having any sick on boai'd on liis anival." He also adds 
"that every preoantion was used, by lighting stoves l)etween 
decks and scrubbing with hot sand, to insure the most thor- 
ough drj'ness, and every means put in practice to promote 
cheerfulness among the men. "When in command of tlie Re- 
cruit gun-brig, Avbieh lay about nine weeks at Vera Cruz, the 
same meaus preserved the health of his crew, when the other 
shifts of war anchored around him lost from twenty to fifty 
men cju'li ; and although constant communication was maintain- 
ed Itetween the Ileeruit and the other vessels, and all were ex- 
ix>sed to the same external causes of disease, no case of sickness 
occurred ou board the Recruit." 

When flannel is first jiut on it often causes an exceedingly 
impleasant itching, which may be avoided by wearing linen or 
cotton under it ; liut the practice shoidd be avoided if possible, 
for it seriously inteiferes with the liygicuic properties of the 
flannel. Aged and infirm ])eople should wear it all the year; 
and if those who are subject to rheumatifim, or predisposed to 
grave pulmonary disease, would adojit the eame practice, it 
would be gi'eatly to their ad\antage. 

Stockings, thongh a modem discoven. have become an indis- 
pensable article of clothing for adults. The singidar eftects of 
exposure of the feet to cold and wet are known to all, yet how 
careless most people are in this particular, and how bitterly 
they regret their neglect when a severe ratanh or rlunmiatif-m 
is the jieuidty which outraged nature exacts. In childhood 
many severe attacks of disease might be averted by keeping 
the feet warm and diy; and as middle and old age approach 
the precaution becomes more necessary, for the powers of the 
system to throw oft' disease are less, and, since prevention is al- 
ways better than cure, it is best to wear woolen undergarments 
throughout the year, using heavier material in the winter. 

of flannel be nYuiilul ? Wlijr gliunlJ c«|ic('iiil 



240 



USE OF C0HSET3. 



The garments that are wora next the skin should be clianged 
bet'oie thfv heeoiue saturated with secretions of the sebaceous 
glamli. This can be accoinplislied by renewing them al>out 
tmee a week, though the majority of peojilw only change them 
once in the same peritKl; but it is not sufficient. Cleau clutb- 
ing should always be well aired and dried, especially in the 
case of invalids. In certain northern conn tries, when a poor sick 
person is oi-dered a change of linen, it is the custom for a frieml 
or relative to wear it for some days in order that it may 1« 
weU aiieil. The effect of such a system is to render it utterly 
unfit tor use, for it is permeated with the secretions of the akin 
of the first wearer; and, if he has been in the vicinity of,or is 
himself auffering from any conti^ous disease, it is very liable 
to be imparted to the sick man. 

The shape oi" eut of the clothes has a certain amount of infla- 
ence on the health of the weai-er. In hot countries they should 
be ample and !o<i8e, f^o that the air they contain may be readily 
and freijuently changed, and the emanations fmm the skin n*- 
moved. Illustrations of this principle are afforded by the Per- 
sians, Arabians, and all nations that live in hot countries. In 
cold climates, on tlie contrary, the clothes are nearly always cut 
so as to fit the body closely, and retain the heat as much 
possible. 

As I'egards tlie use of ligatures around any part of the body, 
wliether as stocks or tight neck-ties in men, or tight corset* 
and garters in women, we can only speak in condemnation 
but so long as the fashions of America are originate<I by tlie 
Parisian lorettes, it is useless to attempt to resist any al>surditj- 
they may introduce. For the sake of those who thiuk they 
must employ some such article of dress, we quote the recom- 
mendations of Dr. Goddard, in his essay on tight lacing. lie 
says : " 1st. Corsets sliouUl be made of smooth, soft, elastic ma- 
terials ; 2d. They should be accurately fitted, and uuKlified to 
suit the peculiarities of figure of each wearer; od. No other 
stiff'ening should be used l)ut that of cmilting or padding: the 
bones, steel, etc., should be left to tlie defonnetl or diseaseil.for 
whom they were originally intended; 4tli. Corsets should nev- 
er be drawn so tiglit as to im])ede regular natural breathing, 
as, under all circumstances, the improvement of figure is insuf- 

Ilniv oficn alioiilil tlip enrnicntii noxl tlio »kiii lu cban)^ ? Wtiv ilicialJ cloihing be airtJ 
befiiro it ■» put (in? Wlint cnl or fhtyie sliuuhl Im eWen \o (lie clnlhrM? What dlflFrcim 
In )ho mclhoil of >:iittinf: utmulil bn cmjilnml in UifTcrcnt clinmlcsP Arc curwia and tnck 
menni of vumpresEian licalih}'? Hq^v iliould cornets bo canstructod and norn wbcn tb*/' 



ABSORPTION OF ElIAKATIONS BY DARK CLOXIIIXO. 241 

ficient to compensate for the air of a\vkwanl I'ostraint caused 
by sufli lacing ; oth. They should never be worn, either loosely 
or tightly, during the hours appropriated to sleep, as, by im- 
peding resjiiratioii, and accunmlatiDg the heat of the i^ystem ini- 
pitiperly, they invariably injure ; Oth. The corset for young per- 
wuis nliould be of the simplest character, and worn in the litrht- 
est and easiest manner, allowing the lungs full play, and giving 
the form its fidl opportunity for ex])an8inn." 

We have, in a previous lecture, drawn attention to the ex- 
periments of Franklin and Davy, which demonstrated that dit- 
iei-ent^cwlored sui-taces absorbed light \Nith different degrees of 
I'apidity ; we now advance those of Dr. Stark on the power of 
cloth of different colors to absorb odors. The sense of smell 
shows that when portions of cloth of various shades are ex- 
posed to odorous gases or vapoi-s, those which are darkest aVi- 
wjrb the odoriferous particles with the greatest avidity. By 
employing camphor, Stark added ot-ular proof of the fact that 
the power of colored nurfaces to altsorb odorous particles de- 
pends on the depth of the color, those which are dark absorb- 
mg often more than twice as much as those which are of a 
Mglit tint. To quote his own language: "If it be thus certain 
Mi:it odorous emanations have not only a particular affinity for 
difi'f rent substances, but that the color of these substances ma- 
terially attects their absorbing or radiating qualitj', the knowl- 
edge of these facts may afford usefid hints tor the preservation 
of the general health during the prevalence of contagious dis- 
ease^. From tlieir minute division and vast range of action, 
latent poisonous exhalations or effluvia, inappreciable }»y the 
balance, may no doubt exist to a dangerous extent without be- 
ing evident to the sense of smell But in most cases it will be 
found that, wheu contagious diseases prevail to such an extent, 
the emanations from the sick will, if attended to, give the surest 
indications of the contamination of the surrounding air. Be- 
sides, even if we allow that infectious emanations have no nec- 
essary connection with o<h)rs, the experiments will afford the 
strongest possible jwesumption that the emanations of an in- 
fectious nature, in common with odors, vapoi-s, and emanations 
generally, are emitted on the one hand, and, on the other, re- 
ceived nceording to the same general laws. Next, therefore, to 
keeping the walls of hospitals, prisons, or apartments occupied 
by a number of individuals of a white color, I should suggest 



242 EFFECTS OF EXERCISE. 

that the bedsteads, tables, seats, etc., should be painted white, 
aud that the dresses of the nuraes and hospital attendants 
should be of a light color. A regulation of this kind would 
possess the double advantage of enabling (ieanliness to be en- 
forced, at the same time that it presented the leai?t absorbent 
surface to the emanations of disease. 

" On the same principle, it would appear that physicians and 
others, by dressing in Uarl; have unluckily choeen the color 
of all others the most absorbent of odorous and other exhala- 
tions, and of course the most dangerous to themselves and par 
tients. Facts have been mentioned which make it next to ctr. 
tain that contagious diseases may be communicated to a third 
person through the medium of one who has been exposed to 
contagion, but hunself not affected." 

Though we may not accept all that Dr. Stark has stated, 
there can be but little doubt that dark-colored sui-faces do ai: 
sfirb odomus and other emanations with greater andity than 
those which are light, and his recommendations regarding the 
dresses of hospital nui-ses aud patients are worthy of serious 
attention. 



LECTURE L. 

HYGIENE OF THE MUSCULAR, OSSEOUS, AND NEBVOUS STBTElCa. 



Exercise necessary to tlie proper Maintenance of the Miucular and Ken- 
oHs Sifitenu. — Forms of Exercise. — Active ami I'aaaiee JCterri»t. 
Wulkiny. — Leupinff. — Itunning. — I}ancinff. — Eencitiff. — Boosing. 
Wrealliiif/. — IToraebtick Eeereise. — Sailirig, — Driving. — Pauive J/ovs- 
merUa of different Limbs. — Amonnt of Exercise required At/ aw ^IiIkA. 
— Incompari/iilitt/ of Labor and Mental Actio it;/. — Cojtditiona re^iti- 
site for the proper Development ofJtone. . 

In order to preserve the muscular and osseous tissues in a 
])erfect state of health, the first must be subjected tti a certAia 
amount of exercise, and the food must be adapted to the prop- 
er nutrition of the latter. 

Exercise, to a suitable extent, is one of the essential condi 
tions of health ; it not only improves the tone of the musculsp 
system, but it also imparts a stuunlns to all the tissues and or- 
gans of the body. Its action on the digestive ajtparatti!^ 18 
universally known, and is appreciated to a greater or less ex- 
tent liv all. 



rOKMS OF ACTIVE EXERCISE. 



243 



j Exercise may be either active or passive. In the first the 
_jau8cle3 are thrown into action l>y the will of the individual ; 
they consequently are nouiishcd with ffi'eater perfection, in- 
crease in size, anil Ijecoine firm and hai-d, and are capable of 
endui-ing an immense amount of fatigue and labor. The fat 
that fills the interstices Wtween the bands that compose the 
nmscles, and that between the muscles themselves, is absorbed, 
and the outlines of these organs are sharply define<l, and.at the 
same time, the limbs gain greater freedom of action. In pas- 
sive exercise, on the contrary, the source of motion is extrane- 
ous to the body, and it is sulijected to a seiies of forced move- 
ments; the organs of the system are stimulated by the succus^ 
sion that attends these movements, and the musdea are thrown 
into activity that varies with the intensity of the original 
cause. In riding on horseback, for example, a very considera- 
ble amount of muscular exertion is necessary in order to retain 
one's seat when the motion is rapid. 

Of all the forms of active exercise, that which is attendant 
on travel is the most beneficial, on account of the constantly re- 
curring changes of air, and tlie continual stimulation of the 
senses by the numei-ous novelties that are ]>re?ented in rapid 
succession. With the improvement in the tone of the nervous 
system that follows on this grateful stimulation of the senses, 
there is increased appetite ; the traveler eats lieartily and sleeps 
soundly; digestion and absorption are benefited, and the tone 
of all the tissues and organs elevated. 
~ Tlie gentlest form of active exercise is walking on a level 

' irface; the muscles of the extremities, trunk, abdomen, and 

!ck are thrown into a moderate action, which does not easily 

duce fatigue. In ascending and descending a hill-side the 

_otion is more violent and the succussion is greater, conse- 

jnently fatigue is more rapidly induced. 

Rowing is an excellent fonii of exercise, which may be adapt- 
ed to all periods of life, fi'om the mere cliild to the old man. 
It is of gi'eat value to young men, since it tends to develop the 

buscles of the chest ; and when the exertion is great, as in 

'icing, nearly all the muscles of the Iwdy and lower extremi- 

.es ai-e also thrown into violent action. 

i The exercise of leaping or jumping jars the body violently ; 

|ia only suitable to the period of youth, when the cartilages 



■0 Ihe fomiBor exercise? How di>r» iiciive p 
' Whn[ form of exerci*!! U mosi Iwiicflciul ? 
IB? How Uoct roning act? Uoiv dctea leaping ncl en 



pn'iiic net? How <lo« pfllskp c 
Whnt i* the genilcEt Torm of cm.' 
I be organs ? 



244 FORMS OF PASSI\-E EXERCISE. 

are soft, and can, by their elasticity, moderate the violence of 
the succussion. In adults and in old people, in whom the car- 
tili^es have become indurated, and have lost, to a certain ex- 
tent> their elasticity, it is highly improper, and is fmjueutly 
followed by serious a)U8equenees. 

In nmning there is a succession of leaps, which quickly pro- 
duces fatigue, and excites the organs of cnvuljiti<»n and resjiira- 
tion violently ; it is also only suited to the earlier i^riods of 
life 

Dancing is a comjxiund of stepping and leaping, frefjuently 
attended by a movement of gyration, and diversiJBed with pe- 
riods of rest: the mind is at the same time stimulated by the 
nuisic, and the brilliant costumes and merry faces aid in mak- 
ing it one of the best forms of exercise when not carried to ex- 
cess. Where there is any oi^auic disease of the heart or longs 
it sbonld be avoided, and at ceitain jienods in tlie livfs of 
women it is apt to produce serious consequences. 

Fencing rapidly develops all the muscles of the up[>er ex- 
tremities, and of the trunk and lower extremities. It al«j ne- 
cessitates great activity of the mind and senses, iu oitler to 
guard against the attack of the opponent. Boxing and wrew- 
tling are very similar iu character to fencing ; they are only 
adapted to the periods of youth and manhooa. 

Of the forms of passive exei-cise we have already stated that 
hoi-seback riding is the best ; next to this ^ve may place riding 
iu a carriage, wliich mav be varied in the intensity of its efiect 
by tlie nature of the velncle. 

Sailing is another form of passive exercise, the effect of which 
depends in a great measure on the change of air aud continued 
succession of novelties, but which also brings to some the long 
train of uncomtbi-table sensations included under the name o^ 
sea-sickness, the explanation of which is still involved iu mys- 
tery ; but, in spite of this drawback, it is one of the Wst forms 
of exercise for the majority of invalids, and is often the most 
valuable remedial agent that can be employed during conv 
lescence. 

When the system is debilitated by disease it is often iDcapft- 
ble of any of the modes of exercise mentioned above ; under 
these circumstancefl, gentler forms of movement are often pro- 
ductive of excellent results. If the sick man is too weak to 



How dues mnpiiiiB iii!i ? Ai whni ]«^riuJs of lift thoulJ Ica^ini; nnO mnnini! bo imlulixd 
in? UnJor what rirvumBlnnuti Rhould ilancint- be nvuidnl? Haw dues fuiiring iin~'baa- 
ing — wrestling? Wlial ii ilic licM fonn of poisiva cxcrciae? llo» dixu iniliiig aaF 



KEACrrON OF TIIE illND AND BODY ON EACH OTHER. 245 



Hvide in a carriage, the use of passive motion, in ivhich the limbs 
'-are moved by another person, and the skin gently rubbed, will 
lie found to aid in improving both the appetite and the action 
of the different organs. 

The amount of exercise required by difierent persons varies 
pivatly, but a walk of four or six miles a day seems to agree 
with tlie constitutions of the majority of men; they eat and 
sleep better, and all the functions of their systems are per- 
formed with gi-eater satisfaction when a certain amount of ex- 
ercise is taken daily. But no definite rule can be established; 
every individual must expenment for himself, and determine 
the amount of physical exertion necessary for the well-being of 
his own system. 

Exercise is, of course, n f?u>»ject of no interest whatever to a 
labonng man ; but to those who follow sedentary pursuits it is 
of vital importance, and efpeciall}' to the student, who is only 
too apt, when carried away by the desire to attain mental and 
intellectual improvement, to forget the absolute necessity of 
paying some attention to the wants of the body. It is to this 
class tliat we Mould earnestly a])i)eal, and urge the necessity of 
spending one or two hours a day in outdoor exercise, that their 
bodies may be fitted to bear the strain which the nervous sjs- 
tem is compellei.1 to endure. 

It is an old saying that a sound mind requires a sound 
body ; yet, though parents are continually repeating it, and ap- 
plying it to the chddren of their neighbors, they rarely apply 
It to their own, but endeavor to drive them through school 
into college or business long before they ai*e fitted jihysically 
for the mental effort to which they ai'e subjected. The evil 
Kosonsequences of such a forcing system are to be seen in every 
^HHrection. How many unfortunate children can every teacher 
^^wint out within the limit of his own experience who have 
been utterly disheartened and discouraged, and have finally 
formed an unconquerable distaste for every vaiiety of mental 
imrsuit, because they have been forced to undertake tasks 
which they were too young and feeble to accomplish. 

Though a certain amount of exercise is necessary to the well- 
being of the system, antl ena>>]ea it to undertake mental labor 
with greater satisfaction and better results, it may be readily 
carried to excess, and produce the opposite effect ; intense, long- 
continued muscular laljor is incompatible \vith intellectual ad- 



UtHler tthtit circuniKtunceB slioald ilririni: nnil tho (uiHsire notion of Kparslo limbs be 
cmplejcd ? What is Ihc nrcrngc amount of exercise required \ij n hcuiiiif uUuli 7 




r 



246 



DEVELOPMENT 0*' ttOS OSSEOUS TISSUE. 



I 



vanceraent. The laborer is too wearj' to study; all Ills nerv- 
ous foi'ce is expeudetl on his niusclcs, and thcro is nothing left 
to stimulate the intt'Uett. 

The osseous systfiti I'equii'es a liberal siipph' of jdiosphntes 
of lime for its [jroper developmeut and 8iiii|)ort ; these iuu»E 
necessarily be lutrodiieed in the food; but, an \vv advance in 
civilisation and in the social scale, it seems as if we endeavored 
to render our bodies more and luoru liable to disease, by chau^ 
ing the character of the diet, and reudeiing it less able to su]> 
jily the wants of the system. 

The greatest demand for phosphates exists dui'ing infaiirj* 
and childhood; they should therefoi-e be supplied most fn-ely 
at this [leriod. Tho mother or nurse should use bread niada 
fi-om flour that retains a pait of the covering of tlie grain ; an* 
^vhen the child is weaned, coarse bninn bivad is a far better t 
tide of diet than tlie fine white l)read, which contains but 
very small proportion of phosphates. 

^\-lE(*^. LECTURE LI. ^ 

l-itOPDYLACTICS. 

nutory of tenner's Discovery of Vaccination, — Quarantine.— 
Conditions that favor the spread of Cholera ami the Fixer*. 
tioH of greets and Public IVncea. — Purif cation ofPrivaU and Ti 
Ilousta. — Pertonnt I'rnphytaxia. — JiiMitity. — Cancer. — /*/"" ' " 

fecU of Intevmarridffes. — Conclusion. 

The last division of the subject of liygiene ia the I 

pTOphylacties, by which we mean the nietliods or dnwvjj 
ployed to enable the system to avoid disease. TJie Wst eia 
pie of such methods is vaccination, for which we are indcbi 
to .Tenner, who noticed that the girls emi)loveil in milking fl 
dairy-farms contracted sores on their bands, derived fniui »m 
ulcers on the teats of the cows, and wei-e not attacked h^ 
small-pox. Suspecting that the vaccinia of the cow-n-at i 
the ardent that protected the milkmaids fi-om the smidl-pox, haB 
submitted his theory to the test of experiment, and found Uia^ 
it was correct. 

Since the introduction of Jenner's system of vaccination, tin 

Are Islnr nnd mcnlnl ni-livily compniililo? Whni » thi- cssenlinl condition lor tbo p> 
or nntriiion cf iho naspoii* ■nii-ni? Ai ivlmi [ffirlnj oTllfii in ihu gn^niMi mipi'lrrifiJ 
phstM rpquired t Whin vnrieiy of brend fnmislics tlie Inrgebl nmonni orphwiilminT "" 
meprophylacliis? What ii tlie hislorf of vwcitwlioii? 



QUAliAXTIKB XSD FOMITES. 



oiall-pox, whicli was liefore liis titiii a tfrnble plague, cany- 
^ ' whole eonimiuiit les in n suasou, has xiLny become so 
BKHlified that it is comparatively rare, and wiareely evtr ap- 
pears among the nations tliat maintain a strict sjstem of \tic- 
ciuation. 

As an example of the employment of drugs as projiliylactics, 
liTre may cite the use of quinine (13 a proteetioii ayaini-t the ma- 
"larial poisons of our Southern States. During the past war it 
■SvMS administered as a regular ration to the troops stationed in 
■■difitriets in which the various types of intermittent and remit- 
■ "tent fevers prevailed, and was found to reduce greatly the pi-o- 
Kportion of such fevers. 

One of the most important prophylactic measures is the 

S"" uarantiue. It is established by all civilized cominnnities for 
_ leir protection against vaiious plagnes, and i« foundetl ujkiu 
Jie fact that such diseases are couvcvhI eitlier liy jiersons nut'- 
l^ring from them, or by contact with mfected clothing, beJiling, 
©r other substances that liave been in contact with the body 
pf a person alflicte<l with a contagious disease. Infected arti- 
cles ai'e called tbrnites, which tei'ni embraces every variety of 
robject, from the sniallest jiiece of clutliing to the largest ships 
and lii iMpitals. 

When Ihe fomites are small, consisting of clothing, bedding, 

and such articles, the (jiiaraiitine \h\\h generally demand that 

they shall be burned, wliile vi'sscls and biiildiTigs are subjected 

to a thorough systeui of piirlHcation Ity fuinigutiiin, ur the use 

©f eohitions of chlorine. Whatever ojiinions may be held re- 

irding the conveyance of contngjous diseases by fomites, the 

Experience of all maritime nations has ehown that the estab- 

fesument of a strict quarantine is the only protection that hu- 

I ingenuity has devised against their advance; and (Imngh 

t may not succeed in arresting them, it is more or less effective 

'm retarding them, and enabling families and c<immimitic8 to 

perfect their anangemeuts for avoiding their influence. 

The teaifiil epidemic scourges which from time to time sweep 

k>ver the whole civilized world may be greatly modified in 

lieir character and reduced in intensity by the adojitii^n of 

•oper liygienic means. We Iiave already seen how the dis- 

ivery of Jenner has lowered the mortality of small-pox; and 

Rhough we do not possess any such specihc jirotectitui as vac- 

fccination in the case of typhoid or typhus fever, yellow fever. 



CHOLERA AND FEVERS. 



and cholera, we can, liy payina; ordinai"y attention to the hy- 
gienic condition of our Greets, houses, persons, and food, reduce 
greatly the chances of being attacked by these diseases. 

The spread of the fevers and cholera is governed by tliree 
conditions : the first is contact with effluvia emanating from the 
persons of individuals or fomites; 2(1, a favorable state of the 
atmosphere ; and, 3d, a favorable condition of the body of the 
individual e.\-posed to the action of poisonous emanations. 

Whatever opinions may be held regai-ding the contagious 
character of certain diseases, even the most ardent supixirtcrs 
of the uon-conta^ous theory do not care to expose themselves 
unnecessarily to tlie chances of contact either with the persons 
or clothing of those who are diseased. AVe allitherefoi'e, rely 
to a certam extent on the quarantine to protect us as far as 
possible from the introduction of fomites which may become 
foci or points of origin of the disease in our great commercial 
cities. 

When the disease has appeared, every one is liable at any 
moment to come in contact with the poison either in the utrei'ti', 
stores, or public conveyances; we should thei-efore insist u]ion 
the careful cleaning of our sti-eets, and the removal of all of 
fensive matter which may by its decomposition render the at- 
mosphere impure, and consei^uently more favorable to the con- 
veyance and extension of the disease by reducing the tone and 
resisting [wiwer of our bodiea 

The cleansing aud use of such disinfecting agents ns the 
chloride of lime in the streets is very inijioilant, but it is equal- 
ly important that the air of our houses should also be puri|]e<l. 
It is said that in many of the houses iu New York the s^ervants 
fii'st light the fires and pump the water out of the ccllaw: 
though this may l>e an exa^eration, we all know that a ilamp 
cellar is the rule and a dry one the exception. In Lecture 
XLVl. it is said that a damp condition of tlie atuiusplien* ia 
peculiarly favoraMe to tlie conveyance of ail volatile exhal* 
tious, and also reduces the tone of the system ; it is therefore 
very important that the cellar of every house, whether private 
or tenement, should be ])roperly cleansed, dried, aud ventilated 
during tlie years when the epi<lemic diseases ai-e raging, if at 
no other time. 

In the winter season the furnace will generally produce a 
sufficient ventilation of the cellar, aud iirevent the foul air en- 
tering the house ; but in the spring antl summer, wlien cholera 
commences to rage with the greatest violence, the furnace la 



PURinCATION OF HOUSES. 249 

then extinguished, niid there is no ventilation nf the cellar. At 
this time the danger which impends may to a t^'eat extent lie 
avuitlcd Ijy placing a sniiill stove in it, in which a iire should 
\»- kept buiTiing continually; I)y opening a communication 
with one of the chinmey-flues and the top ot'the cellar the vcn- 
lilntiiiii will be most complete, for the air which passes doini 
llii' ifiatinga will escaj>e [lartiy by such an opening and partly 
tliiuugh the stove near the tloor, secunng a change of the at- 
niiispiiere in all parts of the space. If the cellar is long it 
would t)e well to place the stove at one extremity, and pass 
the pipe through tlie whole length of the apurtraeut. to secure 
wanntli and ventilation in all its divisions. 

Having provided suitable ventilation, the sewerage should 
bo put in thorough repair, for in many houses the waste-pipes 
leak, and are continually delivering fluids laden with organic 
matter into the eellai-, where they assist in producing noxious 
va])ors, which are also continually arising ti'om soil that has 
been filled in in leveling the streets and lots, and which is com- 
puscil of the woi-st kinds of rubbish. All traps attached to 
basins, baths, and closets should be connected with a four or 
five inch open tube passing out at the roof. By this device 
waste-jtipes are ventilated, and escape of water from the traps 
jirevented. 

Next iu impiutance to the purification of the air of our 
streets and houses is a i>roper attention to the condition of the 
skill ami the cliaractev of the food. Ever}" one should wash 
the whole fiurtlice of the Itody every day, or at least twice a 
week. In these general apjilications fioap should Dot be used 
more than once a week, for it is not desired to i-emove the oily 
secretions too often, but merely wash off the palts that are ex- 
creted so freely in the fonn of perspiration during the warm 
weather. It is not necessary that the body should he inunei-sed 
in water ; a sponge-bath, or wet towel and a basin of tepid wa- 
ter, will answer the purpose perfectly, since the object is to 
keep the surface of the skin clean, and free from all secretions 
^..soluble in water. 

H|. As i-egards the clothing, many recommend that a flannel 
^pbandage should be worn over the abdomen ; hut it is better to 
eKteml the application all over the surface of the body, and 
wear a light tlanuel or merino shirt and drawers all the sum- 
mer: these should be removed at night, and hung up to be 
Idrieil and aired. When the weather is warm, or perspiration 
%a8 been very fi-ee on account of violent exercise or other cause, 



I 



250 DIET IN CHOLERA BEASOXS. 

the flannel imdeM-lotlunj,' should lie chant^ two or tliree 
times a ^veek ; it would be better to change it every day, when 
cii'ciimsta'ni-es permit. 

Cholera and typhoid fever nre both attended by great dis- 
turbance of the digestive apparatus, a severe dian'Injea V>eiiig 
generally one of the firet symptoms tliat atti-aott* the notiee of 
the sufferer ; and there is no doubt that the uhc of some indi- 
gestible article of food, or exposure of the skin to dmuglits 
without suitable protection, is fi'equeutly the exciting cause of 
an attack of cholera or fevei-, which might otherwise nave been 
a%'oided. The eftect of sudden change in the temperature or 
dew point of the air we may avoid by the use of flannel, but 
the avoidance of indigestible articles is only to be accomplished 
by a careful personal observation of each individual r^arding 
the articles of food which agree or disagree with his own di- 
gestive system, and in which lie may be guided by an cxamia 
ation of the lectni-es on food and the methods of cooking. 

In selecting the articles to be employed as food during the 
jirevalenee of cholera, we may, as a general rule, assert that all 
vegetables sold in the great cities ai-e unsafe ; they are i-arely 
fresh, and the best have been generally plucked or gathered 
two or three days before they reiU'h the table. The greateirt 
care should therefore be taken in the jiurchase and selection of 
fruits and vegetables, and it would perhaps be best to avoid 
their use altogether, and adopt a bread and meat diet, to which 
some alcoholic stinndant, tea or coft'ee, is added. Of the alco- 
holic stimulants, whisky and brandy are the best; the differ- 
ent varieties of beer and ale are all laxative in their nature, 
and are very apt to undergo fermentation in the stomachs of 
those unaccustomed to them. The use of Cayenne pepper in 
highly recommended, and, if employed in small quantitiej;, can 
certainly do no harm, and may be productive of great good ; it 
should be employed as a condiment with the meats. 

The last and most important of all the liygienic means is a 
perfect freedom of the mnid from all depressing influences, and 
especially from fear. By adoj)ting and following the simple 
rules laid down in the preceding paragraphs, we jMace our sys- 
tems in the most favorable condition for resisting the attack 
of epidemic diseases, and avoid the causes which tend to pro- 
voke or excite their onslaught. \Vc may tlicrcfore rest assured 
that our chances of escape are great, and when we reflect how 
small a percentage of the population falls under the epidemic, 
it is not in reality as fearful as it at fii-st ajji^ears, and uU may 



rationally feel that a rt;asonal)Ie attention to the laws of liy- 
^ene will insure comparative immunity ft'om such diseases. 

In the division or class of pruphylactica we may include the 
study of the origin of insanity, and the methods hy which it 
may be avoided, One of the most influential causes of the pro- 
duction of insanity is the presence of the disease in one or both 
of the parents. Whenever it is known to exist, the unfortunate 
should not marry ; tor, tliough the disease may not appear in 
the child of such a person, it is lialtle to In-eak out at any time, 
even in the third or fourth generation, blighting the life not 
only of the sufterer, but of all with whom lie is related, since 
they are forced to the sudden realization of the awful fact that 
they too may at any moment be struck down, and forced to 
spend the remainder of their lives in an asylum. Society 
tlierefoi'e demands, as an act of humanity, and a protection of 
its o«'n integrity, that nn insane pei'son should not marry, so 
that with his death the disease may die also. 

In some instances insanity ajipeai-s or is directly produced 
by some intense mental excitement, as that attendmg great 
giief or joy; but it is generally found that even in these cases 
there is a lurking taint in the family, which has been called 
forth by the sudcten excitement. The only cases in which in- 
sanity arises without the existence of some previous taint is 
either after violent irflammation of the brain, or when the pai-- 
ents have been closely i-elated. Both the civil and religious 
la^v have exerted their jxiwer to pi'event the latter custom ; and 
society has so recognized intennan-iage of the members of the 
same family as the chief origin of idiotcy and insanity, that 
when such marriages occur they are universally condemned, 
and the products regarded with suspicion, as being candidates 
at any moment for tiie asylum. 

The effects of any great pojiular or national excitement may 
alwaj-s lie traced in the asylums of a nation by the incTcase in 
the proportion of insane pei'sous, all great "wars, religious dis- 
cussions or revivals invanably producing a disastrous effect 
on those who are disposed, by hereditary taiut, to this feai-ful 
disease. Communities in which there is great activity of mind 
present conditions favorable to the develojtraent of the disease; 
we consefjuently find that, on examining the census statistics, it 
is comparatively rare amoug the Southern slaves, while it is 
common in New England, 

Tliough we can not control the causes which are the imme- 
diate excitants of insanity, v,e can, to a certain extent, prevent 



252 PHTHISIS AND CANCER. 

its increase by a proper attention to the prevention of inter- 
marriages between those who are closely related, or who al- 
ready possess traces of the disease. 

Phthisis and cancer are also peculiarly liable to transmission 
from one generation to another. They may, of course, arise 
spontaneously, but in the great majority of cases they are hered- 
itary ; and so clearly is this fact recognized by physicians, that 
almost the first question put to a person sufteriug from either 
is, " Of what disease did yom* parents die ?" In these cases, as 
in that of insanity, society again demands that it shall ))e pro- 
tected, and frowns upon all marriages in which such a taint is 
known to exist. 

Though the all-important subject of Hygiene deserv'es a far 
more extended consideration than it has received in this work, 
and could of itself fill many volumes, we have given it all the 
space that circumstances allowed, and have presented many 
facts of general interest and importance. If a close examina- 
tion of these should lead to the adoption of a course of living 
which may render the life of even a single individual more en- 
durable or enjoyable, we shall feel that our work has accora- 
plislied its purpose. 



INDEX. 



A. 

Abdominal cavity, 8 ; glands, 4G. 
Aberration, chromatic and spherical, 167- 

173. 
Absorption, G2, CG, 1G3 ; in plants, G7. 
Acetabulum, 20. 
Adipose tissue, 177. 

Age, influence on tempernture of bodj, 1 20. 
Air-cells, 105 ; change of, 225 ; foul, 217 ; 

sac offish, 118. 
Albumen, 52 ; in blood, 72. 
Alcoholic fluids, 212 ; produced in fermenta- 
tion, 54. 
Ale, 213, 214. 
Alexis St. Martin, 58. 
Allotropic form, 120. 
Alveolar process, 17. 
Analysis of bone, 9. 
Anatomy defined, 7. 
Anchovy, 205. 
Angle of femur, 22. 
Animal charcoal, 10; heat, 117; simplest 

form of, 4 ; animals, slaughtering of, 1118. 
Antrum, 17. 

Anns, 35, 44 ; artificial, 44. 
Aorta, 80, 83. 
Apparatus, digestive, 34; lachrymal, 171; 

respiratory, 104; urinaiy, 121. 
Appendix vermiformis, 35, 44. 
Arachnoid, 133. 
Areolar tissue, 1 7G. 
Aristotle, experiment of, 142. 
Artery, 7G, 85. 

Aorta, 80, 83. 

Axillarv, 87. 

Brachiiil, 87. 

Cardiac, 83. 

Can)tid, 86. 

Coeliac Axis, 88. 

Digital, 90. 

Epigastric, 89. 

Femoral, 89. 

Hepatic, 88. 

Iliac, 89. 

Innoniinata, 83. 

Interosseous, 87. 

Mammary, 87. 

Maxillary, 86. 

Occipital, 86. 

Palmar Arch, 87. 

Phrenic, 88. 

Popliteal, 89. 



4i 
«( 
(( 
<i 
«< 
t( 
(( 
l( 

n 

it 
a 
ii 
n 
i( 
(( 
ii 
n 

(C 



Artery, Profunda, 89. 

** Pubic, 89. 

" Kadial, 87. 

" Renal, 88, 123. 

** Si>ermaiic, 88. 

" Splenic, 88. 

•* Subclavian, 86, 87. 

** Superior Mesenteric, 88. 

" Tibial, 90. 

" Ulnar, 87. 
Articulata, nervous system of, 130. 
Artificial anus, 44. 
Asparagus, 204. 
Asses' milk, 52. 
Asthma, 206. 

Auditory canal, 1 50 ; nen;e, 1 54, 156. 
Audubon, experiment of, 146. 
Auricles, 78. 
Aqueous humor, 169 ; vapor, 225, 229, 230. 

B. 

Ball-room, cautions on leaving, 228. 

Bathing, 231. 

Baths, 232. 

Beans, 203. 

Beaumont, Dr., experiments of, 58, 59. 

Beef, 198. 

Beer, 212. 

Beets, 203. 

Berzelius's analysis of bone, 9. 

Bicuspids, 37. 

Bile, 8, 47 ; action of, 57 ; coloring matter in 

faeces, 62 ; regurgitation of, 60. 
Birds, digestive apparatus of, 61, 62; sense 

of smell, 146; voice, 158. 
Black Assize, 217; Hole, 217. 
Bhidder, 121. 
Bloater paste, 205. 
Blonde, milk of, 52. 
Blood, 7, 70 ; change in passing through liver, 

47; reaction of, 71. 
Blood-vessels, 76, 82; of stomach, 41. 
Blow, effect on tongue, 144. 
Bodv, divisions of, 8 ; fluids of, 7 ; tissues of, 

7.' 
Boiling, 201 ; influence on digestibility of 

food, 59. 
Bone, 9 : boiling, 218 ; function of, 7 ; devel- 
opment, 1 2 ; divisions of, 12. 
Bone, Astragalus, 23. 

** Carpal, 22. 

" Clavicle, 21. 

" Coccyx, 20. 



254 



INDEX. 



!Bone, Cranial, 15. 

" Cuboid, 23. 

** Cuneiform, 22 ; of foot, 23. 

** Ethmoid, 16. 

** Extremities, lower, 22; upper, 21. 

** Face, 17, 18. 

** Femur, 22. 

** Fibula, 22. 

** Frontal, l'>, 

** Hand, 22. 

** Humerus, 21. 

** 1 1 void, 18. 

** Ili'um, 20. 

** Innominatum, 20. 

** Lachrymal, 18. 

** Magnum, 22. 

** Malar, 18. 

** Maxillary, 17. 

** Nasal, 17. 

** Occipital, 15. 

*» Os ttdcis, 23. 

" Palate, 18. 

** Parietal, 17. 

** Patella, 23. 

** Petrous, 10, 154. 

** Phalanges of foot, 22. 

** Pisiform, 22. 

** Pubes, 20. 

** Kndius. 21. 

** Pibs, 10. 

** Sacrum, 20. 

** Scaphoid, 22, 23. 

** Scapula, 21. 

'* Sphenoid, 15. 

** Sternum, 20. 

** Tai-sal, 23. 

" Temporal, IG. 

»* Tibia, 22. 

** Trunk, 18. 

»* Turbinated, 18. 

" Ulna, 21. 

** Unciform, 22. 

*' Vertebral, 18, • , 

• ** Vomer, 18. ' 
Bouquet, 213. 
Brain, 132. 
Brande Table, 213. 
Brand V, 215. 

Bread-making, 55 ; varieties of, 5G. 
Broiling, 50, 201. 
Bronchi, 105. 
Bronchitis, 1 10. 
Brunncr's glands, 49. 
Brunette, milk of, 52. 

C. 

Cabbage, 204. 

Cfccuni. 35, 43 ; of fowl, 01, 
Calorifacient fi>od, 53. 
Canaliculi of bone, II. 
Cancer, 00, 100, 252. 
Canines, 37. 
Capillaries, 70, 77. 

Capillary attraction, 03 ; bronchi, 105; tubes, 
motion in, 03 ; continuoos flow in, 64. 



Cnrbo-hjdrates, 54. 

Carbolic acid, 222. 

Carbon, action of light on compounds of, 1G5; 

oxidation of, 110. 
Carbonic acid, 03; expired. 111 ; produced in 

fermentation, 54. 
Carburetted hydrogen, 218. 
Cardiac opening of stomach, 41. 
Carnivora, digestive canal of, GI ; eyes of, 

176; as food, 107; sense of smell iii, 145; 

teeth of, 38. 
Carolina potato, 204. 
Carrots, 203. 
Cartilage, bone deposited in, 12 ; function of, 

7 ; in joints, 25. 
Casein, 52. 

Castration of animals, 199. 
Cataract, 175. 
Cauliflower, 204. 
Caviare, 201. 
Cavities of body, 8. 
Celery, 204. 
Cells, anatomy of, 8, 4 ; of lung, 105, 106; 

of muscle, 26; nerve, 128; nucleated, 4; 

reproduction, 5. 
Cellulose, 62. 

Cerebellum, 132, 134; function of, 138. 
Cerebro-spinal axis, 132. 
Cerebrum, 132. 
Cerements, 238. 
Cervical vertebrte, 18. 
Champagne. 212, 213. 
Charcoal, 222 ; animal, 10. 
Cheeks, 88. 
Cheese, 194. 
Chemical ra3rs, 164. 
Chewing tobacco, habit of, 216. 
Chilblain, 228. 
Chimimnzee skull, 185. 
Chloride of lime, 222 ; goda, 222 ; sodiam, 

use in svstem, 56. 
Chlorine, 218, 222. 
Chocolate, 211. 
Choke-damp, 218, 
Cholera, 248. 

Cholesterine, 47; on nen'es, 129. 
Choroid, 108. 

Chyle, 8, 57 ; corpuscles, 70. 
Chvme, 7. 50. 
Cider, 214. 
Cinnamon, 206. . 
Circle of Willis, 86. "^ 
Circulation of blood, 91, 92. 
Claret, 214. 
Climate influence on blood, 71 ; on intellect, 

229 ; on diet, 206. 
Clot, 71,74. 
Clothing. 237, 240. 
Cloves, 20<». 

Coats of eyeball, 168 ; intestine, 41 ; stomach, 40. 
Cochlea, 153, 156. 
Cockspur, 101. 
Coffee, 210. 

Cold-blooded animals, 118 ; effects of, 227. 
Colic, 42. 



iin)Ex. 



255 



Colon, 35,' 41. 
ColorHtion, 163. 
Colosiriiin, 100. 
Coma, Vl'i. 

Comets, vnriations of, 160. 
Composition of blood, 71 ; milk, 52; muscle, 
2:>. 

Condiments, 20r». 

Conjunctivii, 171. 

Connective tissue, 176. 

Constipiition, 207. 

Consumption, 117, 193, 226. 

Contagion, 248. 

Corn, 203. 

Corns, 101. 

Corpuscles, 70, 74 ; colostra], 100. 

(Corsets, 240. 

Cotton clothing, 237. 

Cows' milk, 52. 

Crammiup:, IDD. 

Cninial cavity, 8 ; nerves, 134. 

Cream, li)4. 

Croup, 1 16. 

Crystalline humor, 170, 172. 

Cucumbers, 204. 

Curd, 194. 

Currents in oi-enn, 183. 

Cin"ves of vertebrie, 19. 

Cuticle, function of, 140. 

Cutis vera, 100, 103. 

Cylindroid e|>ithelium of villas, 69. 

Cystic duct, 34. 

D. 

Dancing, 244. 

Daw's exf>erimeuts, 172, 237. 

Death, 181. 

Deleau's experiments, 159. 

DiaJysis, 6.'>. 

Diarrhoea, 52. 

Diet influence on milk, 193. 

Dilfiision, 108. 

Digestion, 56; in birds, 61 ; mechanicnl the- 
ory, 58. 

Digestive apparatus, 34 ; juices, 8. 

Digitals, 87. 

Dipping, 215. 

Discs. 74, 75. 

Diseases of lK)nes, 12 ; joints, 25 ; respiratory 
apparatus, 116. 

Disinfectants, 222. 

Distillation of water, 210. 

Diversity of origin, 184. 

Divisions of bones, 12 ; digestive apparatus, 
35: food, 51 ; intestines, 41, 43; Physiolo- 
g}', 6 ; temporal bone, 15. 

Draper, J. C, experiments on respiration, 
111. 

Draper, J. W., theory of circulation, 92. 

Draughts, 219, 236. 

Dromedary, colon of, 61. 

Dryness, eff*ects of, 224, 229. 

Duct of pancretis, 48 ; sublingual, 45 ; Whar- 
ton's, 45 ; hepatic, 34. 

Ductus communis choledochus, 48. 



Duodenum, 34, 42 ; reaction in, 57. 
Dupuytren's experiments, 207. 
Dura mater. 133. 
Dyspepsia, 202. 

E. 

Ear, 150; comparative anatomy, etc., 157; 
trumpet, 148. 

Eau sucrde, 210. 

Eg^ta, 50. 

Eggs, cooking of, 199. 

Elbow-joint, 21. 

Electricity and allotropic state, 120 ; and cap- 
illary attraction, 64 ; effects on body, 229. 

Elephant, colon of, 61. 

Elephantiasis, 209. 

Embonpoint, 205. 

Emulsion, 57. 

Enamel, 36. 

Endocardium, 78. 

Endolymph, 152. 

Endosmometer, 65. 

Endosmosis, 66. 

Endosteum, 12. 

Epidemics, 247. 

Epidermis, 101. 

Epiglottis. 34, 104, 158. 

Epilepsy, 44. 

Epithelium, 140; in faeces, 62. 

Ergot, 203. 

Esquimaux, food of, 51. 

Ether, 160. 

Excretion, 99. 

Exercise, 242. 

Exosmosis, 66. 

Experiments, respiration. 111. 

Expiration, 107. 

Extractive, 99 ; blood, 72; urine, 124. 

Extremities, 8. 

European skull, 185. 

Eustachian tube, 155. 

Eve, 168. 

Eyelids and eyebrows, 172. 

F. 

Facial angle, 185. 

Facies llippocratica, 181. 

Fteces, 48, 50, 62, 63, 207. 

Fang of tooth, 36. 

Fat in blood, 72 ; disappears in liver, 47. 

Fencing, 244. 

Ferment, 46 ; of gastric juice, 48. 

Fermentation, 54 ; of water, 209. 

Fermented liquors, 212. 

Fevers, 247. 

Fibre, muscular, 26. 

Fibrin, 52. 72. 

Filtration, 210. 

Fire-damp, 218; open, 219. 

Fish, 200. 

Fistula, 43. 

Flannel clothing, 238. 

Flour, analvsis of, 55. 

Flues, 219.' 

Fluids of body, 7. 



^M ^^^^^^^^^H 


^H FlnoridoorcntciDm,3G. 


HoraebaEk riding, 344. 


^H Foo»,ii;t;. 


Hor«mdi»h, 200. 


^H Fot1icle» ofitoiQiu-li, 40, 4S. 


KoQsea, niuaiion of, SS4: disitifcciing, 2tS. 


^^1 Fomiic^. 24T. 


Hnmnn life. peHods of. ITS. 




Ilumidilr. eStKU iif, 9S4, ^30, S30. 


^H giilnr nrtii'lcs of, 1 DO. 


Humors of eie, 109.172. 


^H Fool, iKiiies of, ^3. 


Humor's Museum, ir., 101. 


^^H Furt'B.diH'iihiuiiufBUWa, 110; HscenUing snp, 


Hvdra, ST.. 


^B 


llydrocarbona, Sfl, 


^H Fiticture of b^ne, 19; nkiill, 17. 




^H Frangii^ne, I!I4. 


'lion on f«<Kr. 53. 


^H Fnni. mn or, 142. 


llrEramelrle Mnle nf nir. 3'->9. 


^B Frog ircb. circiilnliun in, 94, 


HigiBnadefiinsI, 7; divisiona of 187. 


^H FnMlbite. !!!!0. 




^H FniiM, 21)4. 




^H Fryins, infliieiire im diiceslibiUir of Tood, B9. 


Ico-wnter. 208. 


^H Funcilon of kidiiev. 123; Uvar, 127; akin, 


Idiiwvncrnti™. HW.. 


^B m;Wultrmh^y,rM. 


Idiot brain, I2T. _^^^H 


^H FumM, 197. 


Idiocv,18U,l!&l. ^^^^M 


^H Funuce», iHO. 


Itn^^wml Tnlve, 43. ^^^^| 




Ileum, 34, 4S, ^^^H 


^^M 


^^^^H 


^M Gall-Mndder. 47. 


^^^^H 


^^m Ganglion, 1^; duly nf, 137; reci«(ering, 137. 


Indian corn. 203. ^^^^^H 


^^1 Gangrene, Si8. 






^^^^^1 


^M GiiNW r^nn inleKli'ie. On. 


Infant, bnlhing nf, 203; btuin of-lSTrimTH 


^H Gailric juice, 48 ; niiiim .>f. r,li. 


pemtnreof. 1-J<1. V 




Influential ganelion, 138. ■ 


^H lion of |.lnni> and iiriimuli, 163; iiiflueni^ 


Inuniiv, 2r.l. ■ 


^H on ni.in.Tlit;, 160. 


JnsectK, eyoa of. 1 73 ; Toice of, 1 .-.8. ■ 


^H Gin, SIS. 


InB|>iration,ln7. ■ 


^H Ginger, Km, 


Imelleelnal life, 170; power nndlnlior ineoa- H 


^H GUnd«,iibdominid, 40; BsUlir}-, 280; Bmn- 


pniibte, B45. ■ 




Inter&rcnee, I«!2. ■ 


^M g.>i<Iiiu, HA; UetiorknliliV, 43, 4U; n»m- 


Inieminrriaite, eft'erts of, 2fil. ^M 


^H m^nv. IllO: imroli.J. 4'.; naliVDrv, 4r.; «»■ 






InlealinHlJuicea.4!>, AB. H 


^H Ijii V, 4.'. : Biidoiipurauii, 103. 


luuutine, dlvtiiuns of. 43. ^H 


^K GIulii'illii. 74. 


Involuntary muscle celli, 26. ^^^^H 


^H Gluten, r.2, sn. 


^^^^M 


^B Goitre. 201). 


labium, 20. ^^^^^H 


^H Growth, mie of, 178. 




^H Gruel, Slu. 


^^^^H 


^H Oaltei, HO, 


Jaw. human, 3fii of nit, 38. ,-, *fl^^^B 
Jejunum. 84. 4f.». *.^_ H JO V 


H Gum., a.-.. 


^H GuBlBtor; nerve, 144. 


^1 


Jointa.23; elbow{2r; hip, 20; wtiat, 22. ■ 


Jumping, 2*3. ■ 


^1 Habit. 207. 




^m Hcmaiin, 74. 


^1 


^M Hair, lO^i. 


Knnearoa, atomnch of, HI. ^| 


^H Harvey's ilionry of ein-iilation, 91. 


Kidney, 121. — ^H 


^H Haver>iBn<»iinL>, 11. 


Knaeken, 233. ^^^H 


^1 Heart, 77; .aiinda ..f. HI. 




^H Hern, exi-ew, 11!); ii'Huence on color, 184; 


^^^^1 


^H latent, r<1 : in spet^lrnni, IGl. 


^^^^H 




Ijichnmnl apiiar>iln*, 174. ^^^^^H 


^1 Hel>e<.ir.-mn, in». l.-,G. 


j^^^H 




Lnciicncid.M: nL'tiotiinlM»Mll,^^^^^H 


^H lierbivom, UiKEsiive cniinl, 01 ; c;es, ITG; 


Liiciamcier. VM. H^^^^^l 


^P >en>e<>fBnidl,U5; leeib, 88. 


Lncmiie of bone, ^^^^^H 


^* Herl^ei, LiOO. 


I«niinn spiralis, l.->2, IM. ^^^^H 




Ijingiiage, 167, ^^^^^^1 


Home-Kii'kJiBHs, 2a7. 


Larrey, ^^^^H 



INDEX. 



257 



Larynx, 34, 104. 

Latent beat, 51. 

Leaping, 243. 

Leek, 2Ud. 

Legumenti, 203. 

Lemons, 245. 

Lenses, 166, 172. 

I^^prosy, 200. 

lettuce, 204. . 

Levers, classies of, 24. 

Lieberkuhn, glands of, 48. 

Life, theories of, 1 ; conditions of maintenance 

of, 2. 
Ligament, olijects of, 7. 
Light, properties of, 159; effects on system, 

229 ; maximum intensity of, 164. 
Lime-water, 208. 
Linen, 237. 
Lips, 2.'). 
Liqueurs, 214. 
Liquors, 2 1 4. 
Liver, 46, 127. 
Lobes of brain, 134 ; of liver, 47 ; of lang, 

106. 
Lobule, 105. 
Longsightedness, 174. 
Lumbar vertebra, 18. 
Lunacy, 183. 

Lung of frog, 119; of reptile, 1 18. 
Lungs, 105, 106, 107. 
Lymph, 8. 
Lympliatics, 74. 

M. 

Afncaroni, 202. 

Madeira, 214. 

Miliaria, 222 ; conveyed by moist air, 230. 

Malleus, 151. 

Mulmsey, 214. 

Malpighian capsule, 122 ; tuft, 125. 

Mnlt liquors, 212. 

Mastication, 56, 60. 

Mastoid process, 15. 

Meals, times of, 187. 

Meats, poisoned, 199. 

Meatus extern us, 16; intemos, 154. 

Meatuses of nose, 145. 

Meconium, 100. 

Medicines, 207; administered to infants, 193. 

Medulla oblongata, 134. 

Melon, 204. 

Membranes of brain, 133 ; serous, 35. 

Mercury in capillary tubes, 64 ; preparations 
of, 37. 

Mesenteric glands, 69, 74; action, 70; dis- 
eases, 70. 

Metatarsus, 23. 

Miasma, 222. 

Milk, 52, 100, 189 ; teeth, 87. 

Mitral valve, 80. 

Modiolus, 152. 

Molars, 37. 

MoUusca, nervous system of, 180. 

Monera, 6. 

Mortality of infants, 195 ; rate of, 180. 






Mortification, 203. 

Mucous membrane, 35, 42, 58. 

Mummies, 238. 

Murray *8 observations, 239. 

Muscles, Biceps, 30. 

** Bipenniform, 29. 

" Buccinator, 29. 

*• Deltoid, 30. 

*' Extremities, lower, 38 ; upper, 80. 

*' Eyes, 174. 

" Glutei, 33. 

•* Head, 29. 

" Iliac, 33. 

" Intercostal, 87. 

'* Latissimus dorsi, 30. 

" Masseter, 29. 

*' Microscopic composition, 26. 

** Obliquus extemus and intern us, 30. 

" Occipito-frontalis, 29. 

*' Orbiculaiis oris, 29, 35 ; palpebra- 
rum, 29. 
Pectoralis mnjor and minor, 30. 
Penniform, 29. 

" Psoas, 83. 

** l^diate, 29. 

'* Kectus abdominalis, 30; fcmoris. 
33. 

•* Sartorius, 33. 

*' Stemo-cleido-mastoid, 30. 

" ^Temporal, 29. 

** * Tensor tympanj, 1 55. 

** TibiaUs anticas, 83. 

*' Transversalis, 80. 

•* Trapezius, 29, 30. 

" Triceps, 80. 

** Trunk, 30. 

'^ Vastus extemus and internus, 88. 
Muscular tissue, 25. 
Mushrooms, 204. 
Must, 218. 
Mustard, 206. 
Mutton, 198. 

N. 

Nails, 102. 

Nasal cavity, 8. 

Negro skull, 185. 

Nerves, cranial, 184 ; spinal, 135 ; of teeth, 
36; gustatory, 1 44 ; pneumogastric, 41. 

Nervous force, origin of, 127; tissue, 7. 

Nervous system, 1 27 ; of molluscs, 130; rela- 
tion to animal heat, 119. 

Neuralgia, 36. 

Newton's theory of light, 159. 

Nitrogen, 63. 

Nitrogenized food, 52. 

Non-nitrogen ized food, 52, 58. 

Nostalgia, 227. 

Nucleolus, 4. 

Nucleus, 8. 

Nurse, choice of, 1 98. 

Nursing, 193. 

Nuts, 203. 

Nutmeg, 206. 

Nutritive food, 53. 



R 



o. 

Oilmen), 203. 

I >tciipniion, 233 ; ioflaence on diet, 200, 2-16. 

Oi-ollui, 17:;. 

Utlon nb«ortic<l b; clotliing, S-ll. 

(Esophagus, 8'J ; position, 84 ; entrance tc 



OilH 



r>3. 



>, 4a 



(liiiuns, 203, 200. 
Uiimgikull, 18<>. 
(Irbitul cuTity, 8, 
Urgnns uf nutrition, 7; lecretion and e 

tioii, 7. 
Oi-iginofrace, tlieorieaof, I8(. 
(Iiueiius tixRue, iU; >vsteni,24G. 
(jHiicles, ir>l,lCS. 
(Idtrieh, digoMive canal of, C2. 
(PloliHi, ini', 157. 



I'liine's experiments, 117. 

l-iilme, 17, 84, HO. 

I'Hlninrnrch.aT. 

J'lincrens, 48. 

I'iincrcuiic fluid, 48) itt nclion, 'i7; regurgi- 

tmioLi of, CO. 
Ftipillieofakin, 102,141; tongue, 142. 
I'liiuli.! gluiid, 4Q. 



IMvic cnviiv, 8. 
I'dvis. 20. ' 

I'enetnuing poner of lena, 1G7. 
I'eiBiir, 48. 
I'epliiiien, 'i6. 
J'ericni'iliuMi, 77. 
Terilympb, Ui'J. 
I, 13. 



Pciituneiim, 40. 



I'ei 



,311. 



ren|>irHtion, HO, Ifll. 

Ferttr's [ilnleH, 43, 40. 

PliiiUngcii, 23. 

Ilmrrnx.Sl.a.'), IIH. 

I'liiiBplinie of sudn, 78 ; lime, SO, 73 ; in trs- 

I'liu^horeitKd hydrogen, 03. 

riioii|)li[)ru<i in nervous ijsiem, I '27. 

riitliixiK. 117. 2r>2. 

PJivsicul nicentt, influence on animnts and 

ptunt;!, 184. 
I'liysiiilo)^ defiood, '- 



170. 1 



I'innH, I.'iH, 1*34. 
l>i.><i<:»ii, 102. 
ri|>e« for waier, 309 
I'Junliir nrcli, 00. 
riiinn, idiMorplion ii 
liunl dmclopcd in, 



Plates of I'eyer, 43, 49. 
Plenm, 107. 
Pleurisy, IIC. 
Pneumoniu, 110. 
Poisoning by ments, 199. 
I'oleiitn, 208. 

PolvpR, ST.. 

I'oiliine MnrebBs, 224, 23.".. 

l'orl.21-1. 

Poriul circnlaiiun In kidnev. 124. 

Fotnto, 208; coolting of, 204. 

PrcMiire, ap|iliration ot, 141. 

PriHQia, 101, lUU. 

J'rophjliictics, 2(0. 

Proloplnsm, U. 

I'ljnline, 4G. f.C. 

Pubic nrcli, 20. 

I'liddings, 202. 

Pulmonary blood-i-essel>, 62 ; circulation, 95. 



Puls<v 



IS of b( 



Rndinta, nenous system or, ISO. 

lindish, 203. 

Itain, 208. 

Keccpinculnm chjii, C9. 

lleHiiin,»;,44. 

ReBi=.le.]r.E gnnglion, 137. 

KiiKcciion of iicl't, l(il ; of sound, 14S. 

IMniwion uf light, 163. 

Refinngibiiify of liitTerent colors, 103. 

Reptiles uwd at fowl, 2i)0. 

Keti|nraliun, 104; siiigeii of, 107. 

Resgarainry npiMiniluii, liygieiie of, 217; ot 

6>>||,1I8; fijud,Ii3i instrument, 1 1 2. 
Relino, 149, l.'iO. 
lilietironitmn, 2.'i; oflioort, 78. 
liii^o, 208. 
Ki['keti>, 10. 
Uomtting, 201 ; influence of, on digesiibilitT 

ItodeiiliH, leeih of, 38. 
Itoman bnihs, 281. 
U.K.I of lung, 105. 
Roiviug. 24J. 

Uiiininnnt, Kiomacb of, GO. 
RinmiHg. 244. 
Uiiissinti bulbs, 234. 
Rvo, 202. 



Sncciile, liiS. 

ivii-ks, 214. 

SfliliTiB, 244. 

Siilivii, action of, 54 ; asijsts gastric juice, &' ; 

efttit on laitc, 144; mised, 40; eubmaxU- 

lary, 40. 



SaliTDTy glands, i-i. 

Siilc,20,>; iciioii on taste, 141 ; in 

decomposiliun of, 4S. 
Sails in urine, 134. 
Sap. 67, 70. 

Scaln ve«tibuli and Ijmpani, ISS. 
Schneiiierinn loeinbrane, US. 



Scleio 



,108. 



Sen-bnlliing, 231!. 

Seiuon, effevt on ntoaTS, 197. 

iSebnceouH glnnda, 103. 

Secretiun, IKI 1 iiitentine, 40; 

Seleciing power nf tnembran 

Semicircuinr cBniil4, In'J, o', 

Semiliinnr bone, '2'i ; vnlvai, 

Sensts, 140. 

ScroiiB roombmnoB, 85, 40. 

Senim. 71. 

Sex, effect on blood, 71 ; on 

Sbampnoing, '2'ii. 

Shall-luh. -MO. 

Sherry, HU. 

Shock in b.Uliiitg,S.1!!. 

8!ionsigliKidnes.i, 175. 

Slioalder-joini, 21. 

Sigmoid naxura, 85, 44. 

Silicate of lime, 80. 

Silt doihing, 2'" 



s of hi 

1,0; b 



n. iK). 



a composing, 15. 
Skin.KKI; diaeases of, 200; hjrgiene of, 281. 
Skull, measurement of, IBu. 
Slee[>. 1 »■'. 
ISlaginnit, 320. 
Smelt, 144. 
Smoking, 215. 
Snuls, 201. 
Snntr, 21.'>. 

Soai), bubble diffnsion, 109 ; use of, 281. 
Sodii derived from salt, 46; wnler, 210,212. 
Song, 1 58. 
Sound, properties of, 14G. 

Sources of heat ot bodv, 1 19. 
Speciiil seiiBos. T. 
Spectram, Ifil, 1G2. 
Speech. ir,a. 

Spheroidal epithelium. 99. 
Spicea, 20ri. 
Spinach, 2()4. 
SpinulcDi'd, 134 



H proi 



» (.f vertebrte, 19. 



Spongiolos. HI. 
Springs, 208 ; ivoier, zax. 
Spurred r;e, 203. 
Squamous pmceaa, 16. 
Squlntiiift, 175. 

Starch, ri'i, .'t7, 02. 
Stark's cxpecitnents, 241. 
Krenm coils, 220. 
Steno's duct, 4.i. 

Stomach, 34, 39; nbsnrption, 69 ; content, 40; 
kangaroo, Gl ; ruminant, GO ; shape of; 40. 



Stomnta, 67. 

Slrabii'mas, 175. 

Striped n I uncle fibre, 26. 

Study, effect on urine, 128. 

Sturgeon, 901. 

Sublingual glands, 45; submaxillar}', 45. 

Subsiaoiia osioidea, 36. 

Sugar, G3, 208, 2tH -. acted on bj panci'ealic 

juice, 57; fermenintion, 54; in liver, 4T; 

milk, 52; reHning, 10; ships, 223. 
S<dphurolted hjamgen, 63, 218. 
Sulphuric acid, effect on blood, 71. 
SntareH, 23. 

Sf mputbeiic 9vst«m, 129, 130. 
Synovial sue, 24. 
Systemic heart, 78; blood-resseU, 88. 

T. 
Tables of circnlalion, 'J7. 
Taluicotiuu operations, 101. 
Tanks fur water, 209. 
Tnnniu, 214. 
Tartar, 2 14. 
Taiite, 1 43. 
Ten, 2l«. 

Teeth, 86, 194; cutting, 38; permanent. 87. 
TemperiTlure, appreciation of, 181; influence 

on fermentation, 64 ; influence on man and 

animals, 120. 
Tendon, 29. 
. Thirst, 207; relieved bj baths, 60. 
Tbonicic covily, 8, 106 ; duel, 69. 
Tistue, miincnlar, 25; wliite fibrons, 24; 

bnihling f.iod, 58. 
Tis.«ues i-omiKhiing body, 7; joints, 28; ori- 
gin and compoiilion of, 8; formation uf, 6; 

ropnniiion of, 182. 
Tonst-wnter, 210. 
Tobacco, 213. 
Tokay, 214. 
Toniulues, SOO. 

Tongue, 39, 143; poaiiion of, 34. 
Tonsils, SO. 
Tootli, 101. 
Tootlinche, 86. 

Touch, 140; location of, 148. ' 

Tmcheii, 104. 
Tniiuing, 216. 
Tmvel, 243. 

Trees, efferc on bimsea, 224. 
TniuMuksion ufiigbt. 162; of iDnnd, 148. 

Tuberculosis, lit 

Tnbenwily, femur, 2;i ; iscbiam, 20. 

ISibuli uriniferi, 122. 

Turkish batb, 136. 

Tunii]), 203. 

Tjmpnnic Cavity and membrane, 150, I5j. 

U. 
Unity of origin, 184, 
Uusiri|)cd muscular fibre, 26. 
Urea, 124. 
Ureters, 121. 



260 



INDEX. 



Uric aciJ, 124. 
Urinary apparatus, 121. 
Urine, 60, 124. 
Utricle, ir,2. 
Uvula, 31). 

V. 

Valves of heart, 79 ; veins, 96. 

Valvals conniventes, 42. 

Variations in temperature, 121. 

Vegetable food, 202 ; simplest form of, 4. 

Vegetative life, 1 79. 

Veins, 76, 90, 91 ; portal, 47, 91. 

Ventilation, 218, 248. 

Ventricles, 78. 

Ventori, principle of, 93. 

Vermicelli, 202. 

Vertebral column, 19. 

Vertebrates, nervous system of, 130. 

Vestibule, 162. 

Villus, 42, 68 ; absorption, 69. 

Vinegar, 206 ; effect on tongue, 144. 

Viscera, temperature of, 120. 

Vitreous humor, 170. 

Voice, 167. 

Voluntary muscle cells, 26. 

Vomiting, 42. 



W. 

Walking, 243. 

Warming, methods of, 219. 

Water, 207, 232 ; in blood, 72 ; introduction 

by baths, 60; long application of, 236; 

warm, use of, 60. 
Waves, J 47; theory of light, 160. 
Weight of human being, 178, 179. 
WelU, 208 ; water, temperature of, 232. 
Welsh rarebit, 194. 
Wetting tubes, 64. 
Wharton^s duct, 46. 
Wheat, 37 ; flour, 202. 
Whey, 194. 
Whisky, 216. 
Whisper, 1.59. 

White fibrous tissue, 24 ; swelling, 25. 
Wilson on diet, 231. 
Winds, 266; action of, 183. 
Wine-making, 66. 
Wines, 213. 
Woolen clothing, 238. 
Wounds of chest, 19 ; joints, 25. 



Zygoma, 1 7. 



TBSENa